If the game ever hits that point - whether its now or in the future - then I could see a cycle where every decade or so a revised rulebook is published to gather together errata, cleaner explanations of existing rules, and any new rules that have been published in the interim. That's basically how Call of Cthulhu works for example and it's on its 7th edition. D&D is in a weird state where everyone expects edition changes to be huge changes to the game because of how 3rd edition brought 20+ years of game development advances into the game all at once, but it doesn't actually have to be that way.