I think the purpose it serves now is fine. Being focused on the community that was built over the past few years is a good idea, allowing them to have a place to talk with each other and still be united as the "DFS" community despite the servers shutting down (which, who knows, might not stay that way forever). There's not much else you can do aside from deleting everything which would be a terrible idea.

I mean like, what purpose should it serve now?

That's up to Disp, but so far it seems like it'll stay and be focused on the community.

What should the Discord do then?

I'm still part of the DFS team, even if the only thing remaining is the discord server now. I'm not interested in most of the current major TF2 servers (redsun, titan.tf, skial, panda) so I don't plan to "change servers/team" or anything, it wouldn't be the same anyways, I'm not going anywhere.

What will you do now?