I guess that is dependent on whether Roon completely closes your account — by which I mean your Roon account, not your Roon subscription — and as part of that process informs Stripe to remove any card details linked to your Roon account.
I’d hazard a guess that Roon keeps your account active, unless you explicitly ask them to remove your details, in the hope that you want to resubscribe at some point. Hence your card details would also remain on file at Stripe, linked back to your Roon account.
I can see why Roon would prefer you to keep a payment method on file, as it undoubtable increases automatic renewals and even in the case of lifetime members allows them to sell gift codes without having to check for payment again.
But I am with you. In that while I can also see the clear advantages to users of having a card on file so that subscriptions can seamlessly auto-renew as the default behaviour. I’d at least like to have the option not to have my card on file and instead re-enter one afresh, should I want to re-subscribe or, as a lifetime member, purchase gift codes.