Gathering Doctors for anniversaries didn't take long to become a really unimaginative and frankly lazy trope...
Which has nothing to do with the way they're written, of course.
And it is still happening, albeit with only one real and one fake Doctor. (And would have been two real Doctors if Eccleston had said yes.)
And I suspect we will end up with aural contributions from at least some of the older Doctors. Which is even more insulting since it says they're good for voicing animated paintings but not for actually appearing.