So the metaverse hype train people have started something called the Open Metaverse Interoperability Group, “to establish technological standards for “bridging virtual worlds.". Or so says this New York Times article:

https://www.nytimes.com/2021/07/10/style/metaverse-virtual-worlds.html​

They have a blog. https://omigroup.org/​

The PR seems to be ahead of the actual progress.