Yes. The featured article notes that they were providing links on their Twitter account. Their quoted defense includes, to paraphrase, the account was /mostly/ discussing open access issues, it wasn’t /primarily/ for sharing pirated materials.

They're an organization who's purpose is to commit copyright infringement. They don't have to be doing the infringement on twitter itself for twitter to reasonably suspend them. Again, they suspend them to prevent the platform being inevitably used for direct infringement or to be used as a guide on where/how to participate in the infringement.

Twitter may not be responsible for user content as per section 230 but it's also not a good idea as a company to step on the toes of intellectual property holders without good reason.

Does Twitter automatically ban everyone using the hashtag #CanHasPDF? That's how scientific papers were spread before SciHub; what Elbakyan did was to move the copyright infringement off Twitter and to a dedicated service.