Chum is explicitly “wild west” so yeah - and this is in no way meant to diminish the efforts by original developers and the chum curators - I do regard it as a less quality software source than a proper Linux distro repo (more like an AUR or PPA all though the comparison might be unfair to the aforementioned).
One property of OBS is that there is no way back - once a package is published, its predecessors are gone. This is in contrast with most Linux distro repos where you usually can roll back.
So breakage if it happens is more permanent in the chum world.
Now all of this is wayyy better quality-wise than the Openrepos sources of course, but most users will have a couple of those enabled in addition to chum.