If matrix moved toward pond style metadata protection I would make the effort to move my social graph on to it and probably support it financially.
As is, I don't see the value proposition of matrix. I am genuinely curious what it is. An update to xmpp? Is it that it is going to be encrypted AND federated? Many popular apps now support default encryption so that isn't much of a selling point. Conversations is federated and is not getting traction the way signal has. Being federated has benefits but they are sort of theoretical and aren't high on most people's list of concerns. Further the value proposition of federated systems is attenuated by it's downsides (slow evolution).
Meanwhile people get killed based on metadata. Seems like a more urgent problem to tackle.