[aciswhat]

I wouldn't consider Discourse/Reddit/Github/etc. to be a messaging app per se, even if some of those have messaging functionality between users...

[westurner]

I digress on the category definition. Public messaging (without PM or DM features) is still messaging; and often far more useful than trying to forward 1:1 messages in order to bring additional participants onboard.

It's worth noting that GH/BB/GL have all foregone PM features; probably for the better in terms of productivity: messaging @all is likely more productive.