Yeah, I think it's to solicit a reaction 100%, but it's not subversive at all. Their intentions are clear. The "coaxed into a snafu" meme hints at the nature of what makes trolling unique versus just flaming. Reading back the last part of that sentence has teleported me back in time about 20 years.

It's definitely subversive, as it's subverting communications norms by being rude in the first place.

I mean in a different sense, in the sense that it is insincere. That's the problem with trolling right there. If you're sincere, it's obviously not trolling.

Argueing that something is trolling because it solicits a reaction, or that because it's disruptive it counts as trolling, doesn't make sense. You can't distinguish trolling without knowing someone's motivations. Posts that could be trolling could just as easily be venting, or bringing up a genuine concern that just happens to be contentious, or etc.

Otherwise, flaming people in general is obviously trolling. That's not the way the word trolling has been used historically.

It's not insincere. Perhaps you mean unkind?

I just looked and plenty of definitions of trolling seem to invoke the same idea of insincerity.