I expect there’s been some increasing call at Twitter to basically ban trump since 2016. I expect it’s mostly grown since the summer or so. I think of this move as being less about the specifics of the event than it is about that event making more people agree with the group that want to ban trump, allowing them to take a stronger action.

I feel like the “Twitter internal politics” explanation is more convincing than eg some small committee of expert moderators looking at trumps tweets and carefully deciding if they break the rules, balancing that with public interest considerations, and deciding if some restrictions should be placed on them