So what would happen if Linus revokes the licence for his contributions? (GPL v2 does not have the word irrevocable. Are we stuck until all his contribs are re

So what would happen if Linus revokes the licence for his contributions? (GPL v2 does not have the word irrevocable. Are we stuck until all his contribs are rewritten. Aren't all contribs to Linux so intertwined as to be derivatives of each other. Which Git commit is a derivative and which isn't?