I think that the photos they have on their front page should be enough to tell you who is their target market.

I've invented this heuristic: if the page that describes the project uses the word "solutions", then they'll attempt to use "open source" to obtain free labour, but will distribute the revenues only amongst those people who actually have control.

Yes. They are a YC company, too: https://mattermost.com/blog/yc-leads-50m-series-b-in-matterm...