Except the fact that you're calling a movement an organization when Antifa by definition is not an organization. Why are you even pushing this so hard?
Holy stuff, has no one ever taught you about "context sensitivity"
In this loving context, yes they're an organization.
They form under one name with a motive, and they are 90% uniformly dressed.
And don't go pulling this "no true organization" fallacy bullstuff.
Antifa IS an organization, they're organized, they form their "protests" and then they hide away like cowards before they can be unmasked. They act in violence and provoke violence. They FORM under a single name for a single purpose, maybe there are the outliers who don't understand what they're actually there for, but Antifa has made it clear they're intentions are to "BashTheFash". Antifa has no leadership so that they can hold no accountability, and then people can go around going "Well
no true organization has a lacking leadership." They're an organization, maybe your forgetin' dictionary doesn't spell out antifa as a synonym, but they have a name and they follow a purpose, they're an organization.
If they're purpose is terroristic in nature, then yes they're terrorists.