I've watched the E3 footage a few more times, and the bit that bothers me the most is the mini-map showing too much information (some of that appears to be related to options that may be under player control ~ e.g. the ! and a few other highlights and details).
As these are probably (hopefully) user configurable this may not be too much hand holding.
A more concrete problem is seen with the 'hidden' passage, which is clearly shown on the minimap before any exploration is done.
IMO the cavern mapping should only show what can be seen ~ the underwater passage should only be visible when Geralt is under the surface of that arm of the pool, and the map-draw distance should be limited, rather than immediately filling in the map. What is visible behind the roots is ok though ~ we can see through it, so the visible area could be drawn. (Questions about the appropriateness of the lighting level not considered).
Is this going to be handled more appropriately in the final version of this type of exploration? As presented, this *isn't* a hidden passage.