If you see the words classic subscription; that is definitely what you have. It looks like maybe you lucked out unless you renewed an old classic subscription last July?
I don't believe the Classic subscription will be available.
Fortunately that is not correct.
You can in fact let a classic subscription lapse and choose to renew at a later date. All you have to do is click renew from your downloads by clicking the OD section. Just do not purchase a new subscription and instead click resubscribe.
Otherwise, you are correct in the way the two OD subscriptions work. Software will not cease to function once the subscription lapses
When it comes to the Stardock ecosystem; nothing beats classic OD. Therefore it is well worth it to keep subscribing anyways.