That is so sad.
I can tell you this for sure (and I know you weren't referring to anyone here), I feel seniority takes priority. If things didn't work out between Paizly and Taz you think I'd get rid of Taz? Heck NO! Or if Zoee didn't get along with her I'd rehome Zoee? NOPE. I even had a back up plan with Cathy in case it didn't work out. But luckily all is well.
As Katie and Jennie said - this is for the best. Those people should go on some kind of do not adopt list though.
Will they be coming back to your house? (hoping for pictures)