When will BFA become part of base game

I had just recently come back to the game in prep for Shadowlands. I was waiting to purchase it until BFA became rolled into the base game. Now with Shadowlands not having an official release date, is there any indication as to when BFA might roll into the base game?

I dont want to spend $40+ just to have to do it again a couple weeks/month or two later. I am sure there are others out there who were going to do the same.

Likely with prepatch on the 13th. Since you’re required to level through BFA after leaving Exiles Reach (at level 10+)