Adhesive and 6 new "lesser" UBs (8 if we visit Assembly and Burst's habitats, which I doubt) will be random encounters in each Ultra Space while the 7 from SM are all scripted events. Adhesive is the lesser UB of Guzzlord's Ultra Space because
>I'm rubber, you're glue
and gluing Guzzlord's mouth shut makes perfect sense as a defense against it. Plus it makes no sense for Nihilego to be all alone in its reef if its whole theme is being a parasite.

Necrozma and the Cosmog family also possibly come from the same Ultra Space and have some sort of symbiotic relationship.