Source?
In the deadline article

‘Doctor Who’s Regeneration: Has The Disney Gamble Paid Off?
'Doctor Who' analysis: the Disney deal, Ncuti Gatwa & Russell T Davies are in the spolight after the end of the latest season.

Although the next season has wrapped, this source predicts the final episode has been left open-ended, with the possibility remaining that Gatwa could regenerate into his successor if he chooses to exit. Gatwa’s agents hadn’t responded to Deadline’s request for comment by press time.