> Refusing to cease by an even organisers order will, yes, result in being escorted out forcefully by security

Sure. But if two groups of people are distributing articles published in the organisation’s own journal, with one of them containing elements of political speech, and the organization censors that one, it’s absolutely valid to ask if anyone in government directed that censorship.

The core of the argument is they should not have been asked to cease distributing their article, that’s literally one of the purposes of an academic conference, plenty of other people were doing it in various ways. The ADA, in claiming it was enforcing its rules, was in fact not following them.