I'd laugh if Filoni and Favreau pulled an end-around on Kathleen Kennedy to make their own Thrawn sequel trilogy, set up by the Mandalorian, that shits all over the "official" sequel trilogy.
The fans would never watch 7, 8 and 9 ever again. Might as well be "Legends" at that point.
If Luke shows up in the Mandalorian, we're halfway there basically.