Strawman, I didn't say it was necessarily coming today, just that there is an unusual amount of dev activity lately hinting at an update in the very near future
I will say, if it's not out by today, we will probably get some kind of bombshell teaser tomorrow. Tdev is not online so maybe he's taking a much-deserved day off? I do not believe they will release it any later than Wednesday as that would be cutting it too close to the holiday.
the final countdown goes only before major updates (edit: usually) even though this seems to be pretty big I didn't check it out yet edit 2: damn I was not ready for THAT Bolide!