I saw from the pic some were long coats and some appeared to have the panda coloration which may be why they were assumed to be mixes? Do they know why the breeder just left the dogs?
The owner was suffering from depression because of the death of his wife. It is possible he is in a mental health hospital. Does not appear to be a breeder just a hoarder.
None of the dogs saved by our rescue appear to be panda colored.
Here is the first one to be groomed, quite a difference before and after.
https://www.facebook.com/gsroc.org/photos/pcb.10154144627519515/10154144625794515/?type=3&theater