According to the information, there are two things to be noted: (1) That a decision hasn’t been made yet; and (2) that this is not precisely due to preference for KDE, but because GNOME is a dog to compile according to Pat. (And it surely must be, if KDE is easier to compile in comparison!)
I sincerely hope Patrick does not decide to drop support for GNOME in Slack. Even though I am a KDE user, advocate and even a “developer” (because I do official translation work), I learned how difficult life could be with a distro that tries to belittle one of the two major desktop environments. Back when dinosaurs roamed the Earth and I used KDE 2.2.2 in Red Hat, I could not use any international keyboard, because the Red Hat teletubbies shipped a broken Qt library, and they left it that way even despite the fact that they knew the issue. I would like a distro that can offer a decent implementation of both GNOME and KDE.