Being obliviated and transfigured is a pretty bad fix, yes. But they're both things that he could have anticipated. I don't know how to get out of that, but V might.

that message is just going to end up in the hands of the obliviated ex-Tom-Riddle we like.

Total obliviation requires more than just a message; it requires brainwashing to recreate the lost personality. Voldemort (I mean past V planning for these contingencies) can find a way. He just needs to shut up and do it! (^_^)