I believe this will cause managing subscriptions to be a lot harder and untrustworthy. I will probably have to sign up for different payment systems I never heard of… the store won’t be able to track when subscriptions expire, and this will open up so much room for fraudulent behavior.
Unless the discounts are significant I don’t see myself going through the 3rd party payments. I already try to avoid subscriptions anyway. But for one off purchases, it’s nice to have options. I think this is a modest win for consumers.