What would I know from 'serious' or Africana?

I dunno, dude. Sometimes you lose me in your brevity and/or tongue-in-cheek or sarcastic language!

My humble point is: "Listen and consider the possibilities."

People in the Caribbean (which the Bahamas isn't... but I'm taking liberty in grouping it there!) have sung the same songs in both working and playing contexts. The chanties of Grenada discussed in another thread in which we both participated, were "used" as launching songs... and then sung also at wakes in a non-working context. People could tell you that they were launching songs all the while performing them on a social occasion in a somewhat different style.

While I know that any song, for example, composed by a Euro-American composer for stage entertainment *might* be adapted to a quite different Afro-Bahamaian "folk" style -- whether for play or work -- I don't think we know that this was the case here. (Do we?) I am suggesting that if "John B" was sung within a set of items of Afro-Bahamian folk material, several items of which are confirmed work-songs, and if it was labeled as a launching song (one of the types of work-songs relevant to Bahamian boating culture), then maybe it's worth holding out the possibility that it was one of the work/play songs that just as easily can be borrowed by a Euro-American composer!