Parmandur
Book-Friend
I personally find this difficult to believe. The idea that there will not be any major changes to D&D in the future just because it is presently riding high in popularity seems somewhat short-sighted. It's inevitable. Popularity and tastes of the game will change. Many of the edition changes in D&D often represent these changes of tastes and game design philosophies.
Personally, I know from my own track record in this hobby that I would and will lose prolonged interest in D&D without those rule upheavals. It undeniably kept my interest fresh and renewed my sense of experiencing the game anew. It's why I jumped from 3 to 3.5e. It's why I jumped from 3.5e to both Pathfinder and 4e. It's why I jumped from PF/4e to 5e. I don't think that I would likely come back if it's just "LotR D&D." I will need more than lipstick on a pig. In contrast, I can pick up Catan. I don't need an update. I can play it for a quick game one day. Put it back on my shelf. And then I will return to it later when enough people want to play it. D&D doesn't really work the same way for me. Sure, it will sit on my shelf, and I may play a few other TTRP games before returning back to it, but the sort of issues that I have when engaging the play experience of D&D is different than my expectations when I engage Catan for play purposes.
However, this willingness to switch editions is apparently not the norm among those who play D&D, which is what WotC found out the hard way. Now they have determined that evergreen is what makes them more money in the short term and long term, while we certainly cannot predict the future, it is safe to say that they will follow the money.