I wouldn't mind if they federated with Matrix. In fact that would be great. I would mind if they try to control it. Which inevitably happens when a major player invests into a FOSS project on a big scale. They'll start to worm themselves into steering groups and then use that influence to get some return on investment and start steering things towards their goals. In Google's case that would mean lock-in and datamining (and ads but I doubt that would ever fly on Matrix)
And indeed like zaik said below, they used to do XMPP and stopped it. XMPP is pretty good too these days by the way. But I prefer Matrix because of its bridges.
And indeed like zaik said below, they used to do XMPP and stopped it. XMPP is pretty good too these days by the way. But I prefer Matrix because of its bridges.