But we're talking about an ugly hack by someone who wants to stick to an old program, so why would these things matter? In terms of absolute numbers, I estimate the current scp will be available on server distros like RHEL for the next 5 years. Then for the next 5 years you will be able to use the binary you preserved during the upgrades. So in 2030 you start building scp based on the last version of OpenSSH that supports it (from 2022?). Of course it's going to be suboptimal, and sooner or later you will have problems! The point is, you have this possibility and the program is not going to disappear like it's happening with proprietary services every day.