tl;dr :
- Hexchat IRC client app development stopped
- Linux Mint team was building IRC client to replace Hexchat
- The team tried Matrix and liked it
- Linux Mint’s communication channels are moving from IRC to Matrix
- The desktop app will be named Matrix to avoid confusion
Why not use Beeper?
You can. It just would not be good as preinstalled thing. Operating systems should not preinstall anything tethered to one server in my opinion.
I like beeper, but it forces you to use a beeper.com account, and the mint devs couldn’t make it autojoin the support room