Thinking about it a bit more yeah, when you stop subscribing you might have to roll back 12 months of updates on your machine, which is pretty odd. Clearly they want to discourage you from doing it.

At least bug fixes are included:

"The license also includes all bugfix updates, more specifically in X.Y.Z version all Z releases are included."

I can understand giving you the major version at the time you bought the subscription but it's a bit stingy to exclude minor version bumps (Y releases).