/b/tard here. If you do public stuff on the internet, it's practically the obligation of the internet to show up and do something stupid.
As far as I can tell, somewhere over the last 15 years, people began to confuse "the internet" with "real life". It's important to know that hosting a public space on the internet is not the same as hosting a public space in real life.
I don't think this is even a so terrible example of trolling. A well run AA group could use it as a teachable moment to reinforce their message. It's certainly memorable.
And the people trolling are probably all hanging out on discord, making friends, having the modern equivalent of old-fashioned fun. Just a bunch of bored people seeing what they can get away with to entertain themselves on the internet.
When I was a kid, the neighborhood boys got caught throwing rocks at cars just because they wanted to see what would happen. They also stuck firecrackers in things. Once some teenagers took a baseball bat to every mailbox on the street while hanging out of a car window. Trolling an AA zoom meeting is significantly less bad than any of that.
I would argue that trolling is actually a bit higher-minded than previous generations of trouble-making. When you're restricted to operating only online, outside of physical space, you have to be a bit more clever in your trouble-making. Clever probing of the world to see how it responds is fun, especially with the constraint of "must be done entirely online". It's also largely harmless, because nobody can get physically hurt, and it leads to better safeguards in our online systems.
If you view trolling in that way, I think it's really a sign that our culture is advancing. If a successful troll is possible, it indicates some kind of weakness that needs to be patched. You can't stop the trolls, so you might as well extract what value you can from their work. Also what and how they troll is a sign of the times. The Trump presidency was fairly predictable if you watched the steady increase in what we'd now call "alt-right" ideology on 4chan. As goes /b/, so goes mainstream culture. I guess, in a way, you could say that trolling is a art.