Talking with Maureen, I told her it wouild be a good idea to have IRC support for the community. I think a lot of people is already there and will appreciate.
We have the IRC channel #zcash on OFTC, FreeNode and Irc2P (plus relayed to Slack) for community support (there's also the development channel #zcash-dev).
The r/zcash subreddit and mailing list was closed in order to funnel the forum community into the officially supported Discourse forum (forum.zcashcommunity.com). I think the same should be done to the chat community... move to only officially supporting Slack channels. That way, the community isn't spread too thinly across the many differing services and servers.
I don't see any issue with continuing support for IRC channels, given how easy it is to relay discussion between Slack and IRC (making them effectively one channel).