I can't really see the point of this whole "aviod this or that date because it interferes with XY".
Neither D4 nor 7D2D are games that you will be done with after one or two weeks.
These are both games with high replayability.
Especially D4 is of course an everlasting grind for the best stuff you can get...so what's the point about "let's avoid the release week"?
Wouldn't it be more like "let's wait several months or even years, then interest in the game will maybe somewhat diminished"?
If you're into both of them, you will get both of them, and play both of them,
if you ask me, this is completely independent from the actual date when the game is initially available.
Of course you can't play both games at the same time, but really, what does matter at the end?
Number of copies sold long term, or a bar on steam statictics that tells you that many people playing simultaneously especially during the first few days?
His point is probably about pulicity, not about playing them.