...no, it was not due to a flag being handled, and you're well aware of that. This was a manual suspension, which means there was a reason behind it.
So... there's a lot of context at play here, much more than what you've put into your post.
First of all, you have a long history of pushing people's buttons and trolling folks in chat. You are perfectly aware of that - heck, you even said something to that effect during the conversation that led to this post.
Second, there was the atmosphere of the room at the time. I'm fairly sure I had made it very clear that if you (general you) weren't trying to be constructive, then I had no patience for you. Things were obviously slightly tense.
You came in and started rehashing the discussion, well aware of the tense state of the room. This led to at least two arguments between you and one other user.
Now, I don't like holding grudges. If someone has sincerely gotten over something they used to do, that's great! But when someone has shown a repeated pattern of behavior with no signs of stopping... that's context that is relevant in managing a situation.
In light of your history, and the fact that things were starting to devolve between you and another user, I put the room in timeout for two minutes.
This room was placed in timeout for 2 minutes; This isn't going anywhere constructive. Let's take two minutes to cool off.
Immediately after that timeout wore off, the conversation resumed with no change. People obviously hadn't taken my hint that the conversation wasn't heading somewhere positive.
I didn't suspend you. I can't; I'm not a moderator here on MSE. But as a Tavern RO, I can understand the decision fairly well. You have a long history of intentionally pushing people's buttons. Today was a bad day to be pushing people's buttons, and you got slapped by a trout when it was felt that you were simply doing exactly that.
If you don't want people to think that you're intentionally pushing people's buttons when you're not, then stop intentionally pushing people's buttons in the first place. Because your history of behavior does actually affect the level of patience people have for putting up with you, and the fact that you've received so many warnings over time means you're less likely to get a warning now and more likely to simply receive a kick.
And finally, three hours is nothing. It's almost the smallest possible manual suspension a moderator can issue. It's a slap on the wrist; nothing more. Let it serve as a warning for the future.