Everything should expire as it was set up, but once that happens, the product should become available again as a new purchase to previous subscribers just as it is available to everyone else. That’s what kmk and everyone would expect.
It’s kind of obvious. If I subscribe and later cancel a newspaper or app store subscription, I will always be able to start the subscription again after a pause. The worst that should happen would be that the new purchase might be more expensive now than an old renewal price I could keep while being subscribed, but I should not be blocked from subscribing again for the majority of subscription products.