Basically, Fortnite is rolling out a new system with user-generated “islands” that can have their own independent rating from the main game. If an island is rated E for everyone or E10+(as opposed to the base game’s rating of T for teen), some of the game’s cosmetics aren’t able to be equipped in those areas. People are upset because 1. they paid for those, and 2. apparently there are inconsistencies between what is allowed and what isn’t.
https://www.eurogamer.net/fortnite-promises-fixes-after-age-ratings-update-frustrates-players-with-inappropriate-cosmetics
Basically, Fortnite is rolling out a new system with user-generated “islands” that can have their own independent rating from the main game. If an island is rated E for everyone or E10+(as opposed to the base game’s rating of T for teen), some of the game’s cosmetics aren’t able to be equipped in those areas. People are upset because 1. they paid for those, and 2. apparently there are inconsistencies between what is allowed and what isn’t.