At this point will FFXIV collapse if all mods and third party tools disappear?

[Renathras]

No. All console players play without mods, and probably a good chunk of PC players. I think some of you drastically underestimate how many people just play the game as-is.

especially if we are going to assume that 'third-party' tools encompasses external sites like Teamcraft or Discord.

Discord the chat program? That'd be like saying you can't have your cell phone next to your computer on a speaker conference call or be on Microsoft Teams. There's a pretty big gulf between programs that interact directly with the game and chat programs. The only direct interaction Discord has (with all games, more or less) is showing your voice chat people in the upper left, but that's an overlay that's not part of the game engine, I think...

I think the only one MIGHT be parsers...

EDIT:

Reread the OP. I'm aware that Discord being banned is stupid and never going to happen, but it was included in the hypothetical. Respond to TheNight if you have a problem with his hypothetical scenario.

In that case, I'd say "TheNight" (we all know it's another Titanmen alt) is a moron, but...I suppose known quantities and all that.