All of those are possibilities. It seems like a big coincidence that a swarm would end up right where the hive had been when you would expect workers to. How about this theory, the hive was about to replace the queen and one virgin had emerged and taken an orientation flight but not mated. You moved the hive and the queen flew out to mate and returned to the old location (or she was out at the time you moved it). The bees in the other hive either still had eggs or another queen cell so they ended up with a queen, and the old location had the one that was out (or already oriented). I'm not saying that Thelytoky isn't also a possibility. It has been documented, but at a rate far less than other things are likely to happen...