Your really not supposed to link them to your MDE. They are supposed I h to be linked to the CM's MDE because additional days will be loaded onto those same cards and once they have been linked, they cannot be unlinked. They are told to link them to their accounts and not to let others put them on their own MDE. I was there and heard the instructions with my own 2 ears.
I guess this is another one of those things that you get different answers from different people at Disney.

My DD has received three sets of plastic guest passes-one at each milestone. They were not re-used. The pre-2016 passes operated the way you stated, but the instructions online say they may be linked and FP' s made by others although of course the CM must accompany guests to the parks. We have used guest passes on two trips this way with no issues. I love this way so much better even with fewer passes.
