Keep in contact with the rescue, IF its meant to be it will be.. If not, being upset about it wont change the fact that the dog is just not meant to be yours.
I have a fondness for Boston terriers..I had 0 interest in these dogs until someone/something higher up the line thought it would be funny to dump the first one into my lap.. I went riding with this lady who had Brutis, my first...He was immaciated and LITERALLY she told me they were going to shoot him because he had "some disorder that caused him to puke every time he ate"... yeah the fact that they had 14 other dogs and weren't feeding everyone enough had nothing to do with it... anyway I took him home, fed him, and he fattened right up.. and my love affair with this short nosed, bulgy eyeballed, gassy breed began. Just amazing dogs..
Anyway every boston I have had since him (4), has pretty much fallen into my lap, so I really believe in the "if its meant to be, it will be" mantra