"smaller custom data centers into public cloud" is talking about their Azure migration, so "multi cloud" would almost certainly mean extending a presence into AWS and/or GCP (or maybe others like OCI).

I'm sorry but I really don't see how you're drawing conclusions about this meaning a move off of Ruby and MySQL entirely. That's a huuuge logical leap away from what is written in this post, and you originally stated it in a way that indicated this was a fact.