That typo is the most useful part of your post ironically, I agree, the EU is pretty much one letter away from becoming the UAE
Lemme help you out here with proper definitions:
extortion
ɪkˈstɔːʃ(ə)n,ɛkˈstɔːʃ(ə)n/
noun
the practice of obtaining something, especially money, through force or threats
Note how it does not preclude situations where the money may have been committed to in the past, it is quite simply the practice of obtaining something through threats. If you don't believe the various direct threats made by EU officials of how there will be no deal unless x or no deal unless y, including the payment in question, constitute threats I can't help you.
It absolutely is extortion, right down to the letter of the dictionary definition. Threats were made, money will (probably) be paid as a result.