I could see that, but I actually disagree, respectfully.
We've indeed reached a place with passing that there's no coming back from, but the plateau is coming. Because of injury issues, lengthening guys' careers, etc., I don't think the TD high marks will move much.
It's not a perfect analogy, but look at wins and innings pitched and pitch counts going down in baseball. I predict we'll see something similar in football, except instead of going down, they'll plateau.
Future teams will more often do one of more of the following:
-use multiple quarterbacks in one game (I actually think this'll happen in the next 10-20 years, as quarterbacks become more homogeneous)
-pull their starting quarterback earlier to avoid injury
-pull back on passing to avoid injury and wear and tear
I also think it will become more of a trend to see players retire earlier.
That's all conjecture on my part, but meh, that's why we're here.