Really bad outcome for Epic. They wanted to be able to add their own store and collect 100% off everything and now they get...nothing.
To buy an app or iAP, its a tap of the button through Apple. This new way means for Epic, people would have to click a link, get re-directed to a website, enter in their credit card info (setup an account?) all for maybe a small discount
Epic wanted it side-by-side.
Huge massive blow to Epic, who also now owes millions to Apple.
Epic wanted the world on a platter, for them, for free. They're not getting that.
What they are getting is the ability to get their whales to sign up directly with them and bypass the 30% commission on those gems or bux or whatever Fortnight uses. That is, the whales that weren't smart enough to have already worked that out on their own (assuming Epic was giving them some sort of discount/enticement to buy outside, since Epic didn't have to pay a commission on that). So... it's a small win for Epic. Arguably a big win for Apple, given the ways it could have gone.
I appreciate that the judge is requiring Epic to pay for their missteps.
I seem to recall there being testimony from Tim Cook, or others, that alluded to the fact that they expected to collect their 30% commission regardless of who handles the IAP, suggesting that having Apple handle everything simply made the bookkeeping easier all around.
The cost of having apps in the app store has been, thus far, $99/year to be in the developer program, plus a 30% commission on sales of apps and IAP. If lots of developers try to do their IAP without Apple getting a commission, Apple may well restructure the cost of having apps in the store to have a much greater up-front cost to the developer (a much larger membership fee for the developer program and/or $X/month to have each app appear in the store, or some such). This will end up benefiting some large developers, and probably hurting some small developers. The folks cheering for this because they think it means everything will be cheaper for end users, are in for a surprise.