Jellyfin has Watch Groups that my (tech-challenged) family uses regularly without my help.
I just added IPTV to my setup, so I haven't tested if they work together. I can't see why they wouldn't. Worse case, have then tune into the same channel as you, it should sync up almost perfectly on its own.
Are you hosting your own server or connecting to a public instance?
It's unclear to me how this project does anything to protect the identity of users or who is talking to whom. It's nice to know my messages can't be read, but if my ISP can see who I'm talking to and how often it's not doing much.
Also how to clients find one another? Tor and i2p sites are notoriously require friends or public wikis to share the addresses.
Yeah, you'll need to spin up a Jellyfin server. It's really easy in docker though, and it shouldn't need a machine too powerful. I've heard of people running it on an rPi4 or old laptops.