Thanks for working on this, looks like they really could use some attention and sources. I added the info you posted (source + link) to the profile now, and don't know about others, but I'm ok with and have no problem with the unverified parents template. We could also remove them as parents, but the problem sometimes is (or perhaps was ?) people are going to re-attache them or when that's not possible create new duplicates for these profiles.
So for some the unverified parents template with a clear explanation is a better option, not sure what's best here though, it might be as John says an imaginary person, to fill a gap and be able to connect a lineage to some Royals..so we could add something about it to the Unverified template to make sure this is clear and not repeated again ?