Every review below 9/10 would be a surprise for me.
I wish there won't be troll reviews of 6/10 this time.
I actually don't have very high expectations regarding the reviews. I think the game will maybe not be rated as high as it deserves (in my opinion). Witcher games are still niche games after all, and -besides the downgrade-discussion- there could arouse some criticisms.
For example the size of the world vs. density of content: W3 has a more realistic attempt here where you don't find loot chests, cave entrances and quests behind every bush, some people could still consider this to feel "empty" and they could criticize that the game does not really encourage free exploring but rather running from one POI to another.
Do I expect every single review to be nothing but glowing positives? Nope. I expect at the very least the fighting system to be fairly divisive, along with the fact that the protagonist is not customisable. But I see little reason to worry about the points you made.
when does the review embargo lift?
I fully expect a troll review from polygon. Though probably 8/10 and not 6/10. I'm interested what score Gameinformer gives the game. Dragon Age Inqusition got a 9.5/10 (lol) so this game better gets a 12/10