More specifically, Twitter is carving out (i.e. divesting) Fabric and selling it to Firebase, which is a wholly owned subsidiary of Google (or perhaps selling it to Google directly).
I think you're right but it's weird how this post is coming from the Firebase blog not a main Google products blog (is there one..?). I guess it makes sense...
Fabric is one of the top dev tools I use for iOS. I wonder what kind of change is in store...