It's ridiculous this is still an issue. If you're going to stop the app from launching until updated, set it up to update itself instead of relying on package managers to update. If you don't feel like the trouble, give it a grace period to continue using the app while package managers catch up.
That being said if you come across this post to solve the issue:
Download the .tar.gz option from the launcher and extract the files to wherever your previous instance is located on your system, for Arch linux at the time of writing this is /opt/discord/
might require being run as sudo and/or some fiddling with the file structure to make sure it matches up and discord launches again