The question though is what actually is meaningful to the people who will buy/play the game? The "anniversary" or the actual updated 5E24?
For the most part anniversaries are just arbitrary dates that we all use to symbolize the passage of time. There is nothing inherently more important about the 50th year versus the 51st year, other than we humans liking numbers on the 5s and 10s in most cases. But at least in this case, what is going to be more important for any of us-- the release of new 5E24 books, or the "50th Anniversary"? I would say that the actual books being released means much more to us than any anniversary, so it doesn't actually matter when the new books appear. Sure, you might get a bit of a bump marketing-wise for being able to release new books in the year that we would demarcate as a worthwhile "anniversary"... but I don't happen to think that that marketing bump would be all that significant over and above the standard marketing we'd have for just "NEW BOOKS!"
Releasing on the 50th Anniversary is nice but not actually necessary-- same way releasing a Baldur's Gate 3 tie-inn product is nice, but not actually necessary. The actual products themselves upon release will garner more than enough marketing push on their own.