Anything that has the word "purchase" in it should be legally mandated that there be a way for users to access it indefinitely: in this case, perhaps making it possible to download with some sort of offline DRM. (You can do this, say, with Audible books that you buy.)

Anything which is cloud-only and may disappear at any time should be labelled something else, like "lease".

Sure, they always argue that you are only "renting" them for a one-time-fee, and that the rent agreement could end at any time for any reason.

But them using the word "purchased" in this very announcement (not a mistranslation btw) gives weight to the argument that this is intentional deception of the customer. An even easier case in Germany, where courts acknowledge that customers don't read the terms of service, so any "surprising" terms hidden in the TOS aren't legally binding.

Not so fast. Every contract must be balanced, otherwise it can be challenged (and likely overruled) in courts.

If they have the right to terminate your license and withdraw access to the content, you should also have the right to terminate the contract and withdraw your money.

It cannot work just for one side without any practical reason.

Exactly. These scumbags are not to be trusted. Ever.