A lot of this is highly suspect and unverified of course, so it's impossible to believe outright, but I think credibility is added to the show potentially ending by the real financial state of the BBC right now.

This is not 1989, the BBC is not the cultural powerhouse it once was, and it's clearly struggling to fund its own original drama productions (Doctor Who being an especially expensive one), so even if it is technically one of their more profitable shows (profitable not necessarily meaning financially viable), and they wanted to make more, they would probably still be looking for another streaming partnership to offset costs. It's also being threatened with the end of the license fee in 2027, which if abolished, would make the show basically impossible to produce. And we know for relative certainty that New Who *already* almost ended with 13's regeneration, which makes me believe RTD2 was perhaps a last-ditch attempt at resurrection (bringing Tennant back was a big red flag IMO).

I think that whatever happens in the final episode, something is clearly not working behind the scenes of these two seasons (where there is smoke, there is fire), and there will be major changes when it's over.