This snap app allows to interact to Hive blockchain using Metamask wallet, which unifies access to multiple chain accounts. But true multichain support means that Hive as a blockchain has ability to interact to other chains. To make it possible some cross chain communication must be implemented (what is out of scope of snap implementation).
Anyway in our dreams we'd like to have Hive blockchain integration to the Cosmos and underlying Atom chain... Hopefully such dreams will someday come true...