Yes, that's true. But according to the Instagram post they're trying to figure out a way to offer a steady supply of slide film. Of course that only makes sense if it isn't just a rebranded film of another manufacturer as probably is the case with the current stock they're selling. I still take it as a good sign that the demand seems to be there (otherwise they wouldn't bother). And this demand may motivate other manufacturers to offer slide film as well.