Except that it can't be celebrated in parochial or personal parishes, no new parishes may be built for the purpose of celebrating TLM, and the Bishops have to go to the Vatican to get permission to have a priest celebrate it: as far as I remember, the Bishops themselves cannot authorize any further celebrations of it than are already taking place. Bishops must also find alternate locations for the celebration of the TLM without erecting new parishes.
The Traditionis Custodes may in theory be designed to deal with Lefebvre's people, but Lefebvrites aren't going to care and aren't going to pay attention to it anyway, since most of them are also sedevacantists. So for right now, it's still being celebrated in FSSP parishes but the question remains: for how long? The Bishop around here said that he's going to "study" it, which I assume means "blow it off" and let the FSSP parish continue to celebrate the Latin mass.