I do similar with my B2B security software too (which doesn't have a cloud component). We have an optional software maintenance, which gets you software update

I do similar with my B2B security software too (which doesn't have a cloud component). We have an optional software maintenance, which gets you software updates and support for the duration of your subscription. If you don't renew your subscription, you get to keep using the last version that was available at that time. Sometimes if a lapsed customer later buys a lot of new licenses relative to the number they already have, I just reinstate their maintenance for free, because it feels like the right thing to do