Are these bash.v.posix diffs still useful? They _seem_ dated...

[L A Walsh]

Since this "https://tiswww.case.edu/php/chet/bash/POSIX"; doesn't
seem to be version specific, I'm assuming these are
in the latest bash version. 

I don't understand the benefit of the differences involving
hashed-commands and recovery behavior. It seemed like these
behaviors may have served a purpose at one time, but now seem
more likely to create an unnecessary failure case.

First behavior: How is it beneficial for bash to
store a non-executable in the command-hash?

And second, related behavior: Not searching for an alternative
in the PATH if the old hashed value stops working.

Is there a reason why the non-posix behavior should remain
or might it be, perhaps, more desirable for the bash behavior
to match the posix behavior?