Discord Canary installer app is outdated in community repository. Make autoupdates for it. Discord doesn’t allow use old versions
As an alternative, there is the official canary version (just download, extract and execute it)
https://discord.com/api/download/canary?platform=linux&format=tar.gz
EDIT: Link updated
Source: https://support.discord.com/hc/en-us/articles/360035675191-Discord-Testing-Clients
EDIT2: What about the browser version?, I believe this is perfect for you if you only want to mess around with new features
Discord and Dicord-Canary are inherited from arch linux. First they go to unstable, then testing and then stable branch in Manjaro. See Manjaro - Branch Compare
That’s wrong way for Discord app
https://archived.forum.manjaro.org/t/discord-refuses-to-update-with-yay/157372/6
Personally, i use webcord instead, as that one doesn’t block you because of a pending update.
https://archlinux.org/packages/community/x86_64/discord-canary/
Flagged out-of-date on 2022-02-11
That’s because Discord uses their own system for testing updates. It has Canary, PTB and Stable clients