This is very different from the old system of buying something like Word (or FCP 7) in a box, getting a few minor updates to fix bugs, and when the new major version came out, you had to pay at least an upgrade fee, if not full price.
This applies to every software product in their store (and Google's Play Store) that is bought for a one-time fee in exchange for a lifetime license in the EU.
In the Oracle vs UsedSoft case, the EU court was taking on this question of what does it mean to "own" a digital product vs "licensing" a digital product. That court came to the conclusion that if you paid a one-time fee for a lifetime license of a digital product then you own that product (no matter what the EULA says) and the first sale doctrine applies, which gives you the right to resell it. On the other hand, if you were paying a fee that only gives you access for a set amount of time (a subscription), then you would just be renting (or "licensing") that product for a certain amount of time and thus wouldn't own it, which means you can't resell that product because it isn't covered by the first sale doctrine.
A subscription expires and would need to be renewed. Your license for FCPX never expires. Since you paid a one-time fee for a license of FCPX that never expires (a lifetime license) your copy of FCPX would be covered Oracle vs UsedSoft in the EU and you could resell it. Paying a one-time fee for something is not a subscription.
If you buy a car with cash, you own that car. You can own/use that car for the rest of your life or you can resell that car. If you lease a car you have a subscription that you must renew to keep using that car and you do not have the right to resell that car. That is basically how the Oracle vs UsedSoft sees software products in the EU.