He would be because he's one of the original four - and the one who still acts, at that.
Gathering Doctors for anniversaries didn't take long to become a really unimaginative and frankly lazy trope - i.e. it worked once - quite apart from the practicalities involved...
That's a writing/implementation issue. Nothing inherently wrong with the premise.
If a story is unimaginative and lazy it was because the writer didn't use enough imaganation and was lazy! That's the part to fix, the writer/writing.
Also, the BBC could've thought bigger, more epic and not force the story in a single 75 minute slot! Try a different format where different Doctors appear in different parts of a story, or different episodes all together.
That all said, seeing an old Ian returning to see a very young Doctor would be a classic moment that I'd love to see!