I somewhat disagree. I think the gold standard would have been for Fortnite to simply increase the prices of IAP purchases on iOS devices to pass the 30% on to consumers who choose to use iOS IAP.

I can't seem to find a rule that says pricing must be the same for IAP as elsewhere in current guidelines:

https://developer.apple.com/app-store/review/guidelines/#sub...

That seems like the best of both worlds in the sense that as a user you can choose to purchase in iOS for convenience or go to Fortnite elsewhere and purchase there for cheaper. This move just seems like Epic wanted to pick a fight, they weren't actually interested in offsetting the Apple cut.