Too little too late. Rust is already taking over, by the 22nd century C will be dead.
I suspect, though, that new successful languages will have automatic memory management, either GC/reference counting or Rust-type borrow checking. There's no reason for a new language with the lack of safety of C.
On other OSes, it really depends on how Apple, Google and Microsoft do their work of "our way or the highway" regarding pushing their safe alternatives.
So for C this would be 44 more years from now, but it gets another extra year for every year it survives, so it isn't far fetched to think C will be around in 2100.
That's a blimp, a shitty blimp.
So it's not even touching on the subject of the competition with Rust.