Probably? Nah, they legit advertise what their users do. Seemingly increasingly so.
Discord has "drops" (in beta for over a year now to be fair as it wasn't super popular), aka the status snippet that shows when and what app you're using gets shared with developers. Basically, what you do on your system gets logged. You can opt out of that, of course, but still they do collect it. Pretty sure they also stored calls and screen recordings at some point (for convenience reasons of course), but there are now too many users for that. At least, I think they no longer do that. But every single thing you type into discord is logged and can be traced back to you with perfect accuracy.
I like discord as a communication platform (as long as you keep the spying in mind) as the devs truly believe in their product and as such have created something truly amazing. It will be a sad day when the enshitification phase begins. It somehow hasn't yet which is very shocking in all honesty. Guess that nitro revenue still more than makes up for the dev and hosting costs.