It seems to be this was also a back door pilot for the Unit spinoff. I wonder if Donna will actually stick around for it? May she and her family will stick around for new stuff. I’m guessing if that happens Tennants Doctor will always be off doing something and that why he can’t help.
It is going to be interesting seeing how they balance it (and actually in the main Doctor Who show as well) when there’s literally an entire second Doctor just sitting there doing nothing. Like anytime they escalate things to world-threatening stakes, it’s going to feel weird that there’s a version of the Doctor there who could absolutely help but just… doesn’t for some reason. Like I know this Doctor’s supposed to be recovering and taking it easy, but it seems a bit out of character for any version of the Doctor to not help when people are in trouble.
I would think they’ll play it that he is off somewhere on an adventure of vacationing somewhere.