I read and wasn't impressed with the first X-Mickey book, and I also have Mickey's Inferno, as that is, IMHO, a historically significant book worth having. It wouldn't surprise me if Papercutz's books did get lost in the shuffle with Joe Books, IDW and Fantagraphics' output.
The cover for Planetary Wars is shown on Papercutz' own webpage, but they still haven't removed X-Mickey #3 from there ...so I don't think we can use the fact that it is listed there to say if it's going to be relesed or not.
Oh my, were they really going to publish X-Mickey #3 with the title "The 13th Piano" instead of "The 13th Floor"? At least comixology got it right. Which makes it even more puzzling since they were using comixology's (serviceable but rather uninspired) translations. I own the first two volumes but now it seems that I have to resort to reading the rest of the series digitally. Well, at least what's available, as I can't seem to find anything beyond vol.20 or any of the shorter stories on-line. Anyway, it's always sad when a Disney comic book series gets cancelled.
When I read this I'm even more grateful that the German version of X-Mickey was finally picked up again and will soon be finished (at least the main series) thanks to our "LTB Premium" series...
Perhaps some other publisher can pick the series up again and also improve the translation. The best way to do it would be printing several issues into one book, like what seems to be happening to PKNA.
IMO it's a great series, perhaps not quite as consistently excellent as PKNA, but certainly similarly good at its best moments, particularly when the best Italian talents are involved. An example is "The 13th Floor": Written by Francesco Artibani and as good as anything he's ever done.