I wonder if Chibnall has perhaps put in a sort of possible way for future writers-or even himself-to restore the time lords a second time.

We know that their bodies are intact, although partially converted, and although the time lords are 'dead' the Cybermasters are a******ish. In "Dark Water" and "Death in Heaven" it's already been elaborated that the dead can become Cybermen, so this isn't exactly new...and they can regenerate. Some have noted that it seems like the Master and at least some of the CM managed to escape.

Maybe the Doctor can somehow use her possibly endless regeneration energy to somehow revive them apart from the conversion/death? Kind of worked for the Daleks....plus at least Gallifrey as a planet is still intact, even if the citadel is in ruins, which makes it a bit easier to bring back the TL from a time lock/pocket universe/end of time situation that made it hard to find it the first place. After all the Curator seemed fairly optimistic about Gallifrey's future.

Again, mainly just speculating here.