Their faq states that the license is valid for the current version (v1) and not for any future versions. So all they have to do is increase the version number when money is tight.
Meh, if they are following the affinity scheme, then a v2 would have a pretty good value add, and is worth it. I paid twice for affinity, and I’m still into the whole suite for less than a few months of creative cloud. Granted, this is one product, but I’d still much prefer a once off and upgrade fee vs a subscription.