A while back I had my Diners Club card as one of my cards in Apple Pay. I noticed that there was a $0.00 pending charge from "MasterCard" immediately after first trying to add it (and another once I got off the phone with them to verify my identity). I don't remember ever seeing that with my other issuers, but still, I wonder if the simple act of adding a card would keep the card active.

If not, you could always do a Starbucks app load after adding your card(s). There appears to be a $10 minimum for each load though so hopefully you either don't have to do that many of them or you really like Starbucks.