We can't see ten years into the future, so, we can't answer that. Assuming github is up, and, Armory's developers don't tear down their source (Although, with the internet, a copy is always available), you could always implement it yourself, but, who says BTC exists in ten years? Who says the protocol is the same?
Eh, impossible to say, all we can say is that the wallet specifications are public as of now, so, someone could now, but, in ten years, :shrug:
You can't really take code out of github. People can always pull earlier commits. Github has this politic of never deleting anything pretty much.