I don’t see the site needing legitimacy from a name and haven’t heard of professionals avoiding it since the design was set to make it attractive for experts and professionals to be welcome so they can provide great answers. Any name change at this point would cause much more confusion IMO since the name is quite established.
Unless there’s formal agreement ...
As to your older question being closed, instead of the newer, see this (long) answer to How should duplicate questions be handled?, in particular:
Which question is the duplicate?
Usually a recent question will be closed as a duplicate of an older
question, but this isn't an absolute rule. The general rule is to keep
the question with the best collection of ...