Hmm... Is it correct to change function signatures without extension version bump? pg_upgraded clusters would remain with old version of these functions. Once we have instances with same extension version but with different signatures of its functions, there is no correct way to refer these functions in future. I think we should do the version bump in this case.
The same for 9ff60273e35cad6e9d3a4adf59d5c2455afe9d9e.