Right? The plaintiff's assertion is that The Donald's tweetings are actually official communications from the president. That would imply at least a couple of other startling things as well. Twitter would be on a par with the government printing office, and the Ninth Circuit Court's Travel Ban block (citing a Trump tweet for justification) would be legitimized (quite a feat too).
The funny thing is that no other Presidential communication venue requires him to listen to critics of that communication, whereas this one would. The plaintiffs say that Don's Twitter account is now an "official public venue" and as such, it amounts to a "public square." But there are already plenty of those, and wouldn't that deprive him of what every other Twitter user has, namely a personal account? Should politicians be forbidden to have personal Twitter accounts? At all levels? What about local regulating bodies?
Further, Obama was tweeting a bit too, but no one suggested this kind of thing in his case. What's different now? Is it somehow more official than before? How so? What specific thing changed to make it so?
The plaintiffs allege that Trump and his aides have used the account to carry out official communications, but I don't recall anyone saying that before now, and I can't think of any clear examples. Merely insinuating this won't cut it, probably.