It may be helpful to state the definition.

Toxic - very harmful or unpleasant in a pervasive or insidious way.

So it is not just about being overused, but also about being subjective. So when people try to communicate with each other, it is better to understand how one defines harmful/unpleasant, but also to see if there is a pervasiveness or an insidiousness to what is being labeled as toxic. That's why I say that people who are restrained by the ToS are not being toxic even if their personality doesn't change.

When I see people saying the FFXIV community is not toxic, the examples they use are usually along the lines of, "Oh I made a mistake in a dungeon and people are willing to stick with the group and not kick me and/or insult me." Obviously, there are exceptions, especially if you're no longer new to the game or if it looks like you're doing it on purpose, but in general, that behavior creates a pleasant, non-toxic environment.

Now let's take a look at Asmongold's experience. Did it create an unpleasant experience for him? Definitely.

Was it harmful? Not really, as long as it stays in game, because he's used to that as a popular streamer. (Real life threats, on the other hand, are definitely harmful and serious matters.) The lines between fans and haters blur sometimes when both groups are obsessed over a celebrity.

Was it pervasive or insidious? No, because that's not how the community behaves in general. And people within the community calling it out shows that, but it doesn't help that they then seemingly blame the community at large as well.

So, is it still bad and people deserve to be banned for disrupting gameplay? Definitely.

But is it toxic? Not according to the definition, especially in light of the bans, which shows it is not an acceptable behavior.