Well, like everything involved in this game... each person has decided on their own interpretation of what "evergreen" represents. Same way everyone came up with their own definition of what "backwards compatible" meant, same way everyone had their own interpretation of what "you can play 5E in the style of previous editions" was.I would consider "publish the 4e rules for the VTT" as a form of wooing people back.
That said? This idea that any part of 5e is in any way actually "evergreen" is frankly silly. It never has been, and their claims otherwise were at absolute best pie-in-the-sky dreaming.
They had said things that were very, very much meant to be understood as "we will never replace these core books." They've already broken that "promise" (which, naturally, they never said outright and made sure to always keep soft-touch and equivocal, so people will eviscerate you for claiming that it was a promise...even though it was literally everything BUT explicitly stated.)
If general patterns hold, 5.5e will last all of 4-6 years before we start hearing rumbles about another round of public playtesting. I fully expect an actual public playtest by 2031 at the absolute latest.
I never had the same interpretation of what their "promise" was for keeping 5E "evergreen". To me... the idea that WotC could never reprint the core foundational rules of the 5E game in a new book after some period of time and after X amount of Xanathar's / Tasha's type splatbooks that added onto or changed various rules of the game is rather silly. That for example, even after they had chosen to print like 10 different 'Xanathar' type books over the next decade that they always still had to keep referencing back to the 5E14 Player's Handbook in order for the 5E game to be considered "evergreen" makes little to no sense in my opinion. And I never held them to that ridiculous standard. After all... books like Level Up and Tales of the Valiant has reprinted the core foundational rules of the 5E game (via the 5E SRD) in their own products and they call themselves "5E" games... so obvious they believe the 5E rules are still in effect.
Other people will draw their line in the sand somewhere else. And that's fine. But it doesn't mean they are right and I am wrong. That's all a matter of personal opinion.