I didn’t open a ticket for this because I could fix the problem WAY faster than DH support, but here’s the story/caveat:
Original situation: I had several databases spread over several (four) servers/“mysql.” hostnames.
The test: I decided to merge/move one database/hostname that was mostly unused.
The result: All of the hostnames, regardless of which server they were on, were merged to the primary database server - NOT just the single database and hostname I selected, leaving “orphaned” databases on (two) servers that no longer have a corresponding hostname pointing to them.
This made quite a mess, as four databases that are spread across two other “un-merged” servers became completely inaccessible. Fortunately I was able to add a “mysqltemp.” hostname to the affected (un-merged) database servers and effect a manual transfer of data to restore mySQL service to the affected domains.
So whatch yer butts kiddies.