We actually had matrix up on running on a cluster built with Talos in AWS. We decided to focus our efforts on Talos instead of maintaining infrastructure. There is a convenience factor for us since it is only three of us.
It's just the few times I've used slack as part of an open community it's been suboptimal, honestly a freenode channel was and is better, anyone looking at something like Talos is likely to have an irc client installed :).