Hmm, I think it is related to the fact EU wants Apple to allow people to sideload apps from other stores.
So if I read Apple's announcement correctly here: https://developer.apple.com/support/core-technology-fee/
Either you stick to only using Apple's store, and nothing changes.
Or you switch to the new business terms that allow you to put your apps on alternative stores, and charge your clients with your own payment system (in other words, you try to bypass Apple completely), and then Apple will ask you to pay a fee. They're just trying to counter EU's decision, by making devs pay a way or another.
I think that for people who just want to use the regular App Store as before, nothing changes.