Let me add my two cents here. I've been wanting to do something like this for some time and as Allan has alluded to, there has been discussions amongst engagement team people around this.
My two cents, and bear with me on my slight rant - I really hate the idea of depending on a web app like riot. It's like admitting that we've lost the whole application space and that we're going browser. I know that is not what is intended, but that will be the perception.
I'd like to do this, but I'd like to start putting resources into creating a viable chat client that works and is designed as a competition to a web app. Maybe that means some kind of contest or something. I'm not really worried about actually writing one after all matrix is an open standard, but the design one that shows the advantage of running something native should be a challenge that we need to meet head on.
That said, we'll table that bit for now. I have talked to Andrea Veri, they are kind of low on sysadmin resources and probably can't help in the immediate future in implementing something.
Seeing as I have some free time; I asked Andrea if it was okay if I could spearhead this particular project. A good way introduce myself back to devops after a long hiatus. He seemed to agree, so I can start looking into at least creating the irc bridge between matrix and some specific rooms - #engagement, #newcomers, and #docs. I've picked these as the kind of contributors we have tend to be quite varied, but also there are differences in culture and etiquette between irc and these other technologies that can be disruptive.
sri