I’m sorry but I don’t know what you are referring to as the “current behavior”.
My understanding at this point is:
If it was intended that we could separately define f() and f(;a) then it wouldn’t matter what order they were defined in and they should both show up in the output of methods(f).
If it is intended that we cannot define both f() and f(;a), then the last one defined should make the other unreachable in all cases, and methods(f) should show the appropriate one.
I think the latter is the intent of the language designers (but I could be wrong), and I think there is a bug either way.