For those that don't want to go back to the Dark side (Reddit), the post referenced a theme (Grey Layout global theme) which got KDE Dev's involved who in reaction removed the listing from the store.
In short - the theme ran code to run a rm -rf on the user's drive which wiped everything during install. Aside from backing up your data religiously, be sure to inspect the code instead of blindly installing for now. KDE Dev's said they will need to do better so I expect some changes are afoot to provide better security.