No. Twitter incorrectly used him as some kind of example. They had also did temp bans on him in the past and also the immature move of removing his check mark.
The harassment was happening WELL before Milo was tweeting the ghostbuster. Milo wrote the article. Milo's tweets weren't anywhere NEAR harassment level. Trolling a famous person on twitter is not harassment and brigading. And as many have already shown the ghostbuster herself was just as guilty in the past of attempts at brigading.
There's even some communication from her where she was actually thrilled the incident would give exposure to her and the movie. Whatever people think of this, Milo didn't cause her any suffering or feeling of being 'unsafe' Other harassers were deplorable. Milo was not in that category.