Don’t resolve the Billie Piper Doctor twist, weaponize it

Honestly if they want to move past the Billie Piper thing without just immediately undoing it, I think they should lean into it instead.

Bring back Eccleston and Piper. Start the season and suddenly they’re both back in a Series 1 / Series 9 style setup with full memories of everything that happened since.

Doctor remembers all regenerations. Rose remembers Bad Wolf, Pete’s World, all of it.

And neither of them knows why.

Make the season a mystery.

“Why are we back here?”
“Why do you look like this?”
“Did regeneration break?”
“Did reality break?”
“Or is this some long-forgotten consequence of Bad Wolf?”

Then reveal Billie wasn’t literally the next Doctor forever, she was some kind of temporal anchor / consequence of regeneration / Bad Wolf weirdness.

You get nostalgia, a mystery box season, and then hand off to a new Doctor cleanly afterward.