Okay let's address a couple of things posted/discussed here... Also, I'm not a PC guru so I can definitely be off with some shit!
1: False advertising
It never can be a false advertising when the product itself is not finished nor released.
The fuck it can. False advertising is the basic off fooling your customer by showing a misrepresentation. If people are making purchases (pre-orders) based on material shown by the marketing team that aren't featured in the actual product then it is false advertising. Just look at how much flak, Peter Molyneux have gotten for always promising things that aren't featured in the game, or how Double Fine screwed over their customers. It's not suddenly OK to do whatever you want prior to release because you will then come clean once the product is actually released. It's shitty practice and shouldn't be done, especially since pre-ordering is such a big market in gaming (It's not like you're buying a car from a shop).
Also regarding cancelling pre-orders... This doesn't work with the Collector's Edition because they are limited and if I'm feeling fooled I can't cancel my copy to show CD RED that I'm displeased, because then someone else will just pick it up instead for more money (because that's how Amazon is).
Notice! I'm not saying I believe CD RED are doing false advertising or that all cases becomes a class action law suit, but they are still damn unethical and shouldn't be sugar coated as a excuse. Marketing should be done fucking right.
2: Trailers versus game play
It seems that a lot of focus have been on comparing trailers versus game play. Now this is always dumb and doesn't work in practise.
All trailers no matter their name (This also implies to the so called "game play trailers") are hand crafted to be done as spectacular as possible. This means you are more so using the engine to create a cinematic cut scene, and you apply all work to this to make it look as special as possible. Lightning, editing etc. This should be obvious by now by customers and seeing as CD RED claimed they re-made one trailer over 50 times (source: Pax2015), it's also common practice by CD RED .
Another small thing that could further differentiate the visual on the content is if the engine have been updated over time which made some visuals look different (not worse in fidelity but different) by changing parameters in filters etc.
3: Why people care
Now in hindsight you could ask yourself why do people care? The game still look gorgeous so obviously people just enjoy whining? In short there are three reasons (Probably more, but here's what I got) why (sane) individuals care.
3.1 Principals. I believe most people don't give a flying toss in this but for a couple of us, this is bloody important (The same reason why I never have touched Steam or any EA games). Being honest with trailers/interviews are important because ultimately it's our money and we've been burned so many times before by bad companies, and that's why it's so important that CD RED still remains "pure" because we don't really have anyone else to fall back on.
3.2 Consistency, with the game constantly changing and being shown on different hardware it's rather hard to properly get a gripe on what sort of quality we actually can expect on different hardware. After all people's PC's are diverse... And while I appreciate all game play videos I find it far more informative to know graphic features and texture quality and how different settings differentiate from themselves than more game play footage which to be honest is more of a spoiler than seeing fire interacting with plants or something.
3.3 Ubisoft. Now essentially the big issue is, Ubisoft cut out graphic features because they couldn't be arsed to optimize it properly for PC. This if anything is the big deal. The fear that CD RED looked at all amazing graphic features, looked at the clock and said "February is not enough" then looked at the clock again and said "May is not enough". This is more of a "sad eye" feeling than anything else, after all we know CD RED delayed it because they needed time to optimize it (as the content was done) but with no information on how the game will actually roll on PC because currently based on their game play videos, it's seems that even a 980 is struggling. With consoles this is far more straight forward, you have locked hardware and people (for some reason) settle on locked graphical settings, but with PC it's rather shitty because you would assume if the game can be played on several year old hardware, two or three 980's would be sufficient for ultra at +60 FPS (or at the very least would be told what to expect prior to release).
4: Where are we now
I don't believe CD RED downgraded the game, the real issue is how they represented their early trailers and trailers have a tendency to always look more sublime than the actual game. All in all it makes little sense seeing as CD RED is still pumping out a lot of game play content which were played on a PC. While some "bad spots" definitely can be found it seems that the concern are more targeting certain areas where the fidelity is bad, rather than the overall.
Also some issues tend to be more on lightning which makes some areas look better/worse than they actually are, it seems more-so that CD RED have some areas where the engine is having issue (the frost effect on the Wild hunt's armour comes to mind) and it's mainly this inconsistency that cause a lot of concern.
Overall it feels like the current issue lies on special effects, such as shadow effects on areas, particle effects like dust flowing in the wind etc. So I truly believe CD RED could avoid another 200 page topic if they were to plan a "Technical game dev. diary." where they highlight special effects etc. It's also one of the few things they can do without spoiler the game and provide the community with some new information.
Random thoughts
With all said and done though, CD RED has been rather elusive with information regarding the PC version, both regarding how the Mouse and Keyboard works, whether monitor ratios are addressed (16:10, 21:9, 4:3, 5:4 etc), how the UI is and how you can customize it as well as actual performance and special effects....
I really want this to be covered before release in a detailed "Tech demo" and the notion that "Story is the focus, technical features are a secondary" is nothing more than PR bullshit (which is fine, mind you... PR is PR after all.) to increase sales for Xbox One (since CD RED are being sponsored by Microsoft) or that "We're saving Ultra settings for the gamers to find out" just gives the consumer a bad taste coming from a developer who have been so (rightfully) proud of the beauty they have achieved with their engine.