Prevent a subscription from being available to purchase in iOS subscription settings

We have some subscription items that we no longer offer for purchase directly in our app. We want to continue supporting them for users that already have them, unless/until they decide to try our new offering or end their subscription. But we do not want to be still offering them for purchase in iOS subscription settings.

Is there a way for us to do this currently? If not, please provide a way to deprecate subscription items so users who do not currently subscribe to them will not be able to purchase them outside our app in subscription settings.

If we were able to do this, it would give us a path to gracefully remove these subscriptions from sale. As it is, we are forced to decide between either supporting them forever or abruptly cutting them off for all the users that have them, neither of which are good options.