The deals were already official. The reason its hitting the news again is they are close to formalizing their exit dates/fees with existing conferences.
It looks like they will all move June 2023 timeframe for the fall 2023 season.
The 4 new SBC schools already moved this year after court fights/settlement with CUSA.
Texas/OU is the last piece that the dates aren't known. It sounds like B12 is angling for an improved media deal to release them from the GoR early.