I unfortunately can't share my source on this, but I can confirm this is absolutely something Ghibli do, and not only that they'll refuse to lift it if you dispute the strike, even if the video doesn't contain any footage or audio from their films and is literally just someone talking about them (even positively!). I need to stress that these aren't regular copyright claims where they take the revenue but otherwise leave you alone; these count as one of the three strikes you can receive before you are banned.
It's inconsistent, they don't seem to do it to every video about them, but if they decide they want to fuck you over, they will go above and beyond to do so. It's absurd that a supposedly reputable publisher is able to abuse the system like this in plain sight.