AFAIK https://matrix.to/#/#lo_canada:mozilla.org is the biggest Canada themed matrix chat room. It's not partnered with Lemmy.ca or anyone and I believe they were asked before and didn't want to partner up.
They specifically don't want to do a discord or telegram bridge iirc.
So we could try to make a Lemmy.ca matrix chat room and bridge it to telegram and discord.
I can take care of the bridging, but it's very easy. Ex discord instructions
I only really use element/Matrix and it's better if everyone only uses those, but i respect that other ppl use discord and telegram and don't want to switch.
This discord server is very cooperative https://discord.gg/gEWcR7w4TW so that would be where the discord channel would be located. You could even join it now to check it out since it's fully operational.
There is no operational matrix or telegram atm.
If you want to do a matrix or telegram, tot set it up now and put the link in the comments.