This is a message intended for when someone updates from one version to the next. So, if you sign up for the subscription when CSS Sculptor v2 is out and we release CSS Sculptor v3... then you update to v3 and you will no longer have access to v2.
You can't continue to use v2 on two computers and have v3 on two others. If you cancel the subscription you can always go back and use the extensions you purchased individually or as part of the suite.
And we are continuing to update all of the products in the essential suite. Even though the suite doesn't exist the individual products from the suite do and you will get updates as if you purchased them individually.