Yeah, it really depends on the couple. What if you gave them any amount of btc and they don't know anything about it. They can't appreciate your gift because they don't know its value. They have to learn about it first so they can use your gift. Not all the people are interested in it. For me, I'm not gonna give bitcoin as a wedding gift, but instead I'm going to give them something that I think they would like it. Like I'm going to give the bride an expensive bag.