I don't think they will count the full two years as the anniversy year, more like from late January 2024 to sometime in 2025, perhaps 50 year from where the last OG core book was published or late januarary 25 depending upon how generoys they want to be with their idea of a year.
Also pretty sure the MM is done already, might already be printed and in a ware house, no UAs for it, and I think the only DMG thing getting playtested is the Bastion rules. A second try on Bastion rules might come in the next UA or the one after that if there is one after that. If they prove too.unpopular after that, I think they will dump them and put a plan B in its place into the DMG.
Also Rolls for Combat explains in a video why parts of the core books, even the PHB could be printed, before the last UA is finished, leaving just printing the last parts and assembling to be done. I'll find the video later.
And his point that the dates may have been "leaked on purpose".
I also think they will want to release them together if possible so they can release collectible gift set version in a slipcase.