I don't think any feature from Tasha will be in the game given how long it is taking for them to add PHB features. In fact at this point I believe that there will be things missing from PHB.
Right now we are missing from the PHB and I am not sure we'll have all of them for release:
Barbarian
Bard
Monk
Paladin
Sorcerer
There too many reaction abilities from most of these. That is probably why they not been added yet.
I am still surprised that they did not have proper reaction system worked before EA, it's so core to D&D.
