Well, if you're distributing a piece of media, you need to have legal access to the piece that you distribute. You can take a 5 second clip of a movie that hasn't been released to Netflix yet, broadcast it on X or YouTube, meet all the requisites of fair use, and it's not legal speech; you had no legal access to the media you're redistributing. The speech itself is criminal violation of copyright, because of the lack of legal rights to the media in the first place, secondary to any piracy concerns.

If Studio Ghibli were to take them to court, they'd have to show that they had legal access to the media they're redistributing, namely the frames from the various movies. I believe that in this case they're using frames directly from the official Ghibli site, so there's no ambiguity, but if they purchased each and every movie they index, they'd have an extraordinarily strong case for fair use even without linking back to the studio site.