Anywho, those are my predictions of a 6e. Rather than driven by sales, I think a driving factor will be how the gaming community views design today. I.e., things like race and alignment and the problematic issues therein.
On this, I also disagree.
I think we often tend to overlook both how successful the current iteration of D&D is, and how much D&D is just a "brand" for Hasbro.
We are three years away from the 50th anniversary of D&D. I am sure that they will have all sorts of events planned, and maybe some reprints of classic books, etc. (although with the prevalence of on demand .pdf publishing, maybe not ... perhaps just some deluxe "add-on" art editions).
In terms of a new edition, I truly believe that they intend to keep this as the default "evergreen" edition for as long as sales and cultural cachet permit. I am sure there will be a point, in the future, when a "6e" or a re-vamped 5e (or maybe they will do away with that and it will just be D&D) will be unleashed to goose sales, but we seem to be far from that point.
After all, with movies and TV shows and videogames on the horizon, why bother screwing with the ruleset?
TLDR; Hasbro is a corporation. It's always driven by sales.