If the recipients were moving to another country, in all probability they decided to just get rid of everything, or perhaps the quilt wasn't something that fit in with their idea of decor, or any of many other reasons it might have ended up at Goodwill. I've given many nice things to Goodwill or the Salvation Army (including several wedding gifts)and felt good about giving something nice that somebody else might then buy and love. I wouldn't spend a lot of time feeling hurt, just reveling in the amazing way you got it back! I don't agree with displaying it at a future time when you know the original recipients will see it, either. That seems a little spiteful and unnecessary and likely to cause hurt. Let it go!
Dana