If you want to publish a retro-gaming emulator as a hobby/open-source project, you can’t do that on Apple’s app store. And on a third-party app store you’ll have to pay Apple millions once it becomes popular (which would seem likely).
Since apps are still subject to Apple’s review process even on third-party app stores, they are likely to reject this because it obviously circumvents the new business terms (if it doesn’t violate them outright).
This is only adding new alternative choices, not changing or removing any current systems and methods and prices.