Whether or not this is gambling is still up for debate, but it seems that Apple wants to steer clear of it and according to Touch Arcade, Apple has recently updated its App Store Review Guidelines where it now requires who implement loot boxes into their apps to disclose the odds of gamers getting what they want.
According to section 3.1.1, “Apps offering “loot boxes” or other mechanisms that provide randomized virtual items for purchase must disclose the odds of receiving each type of item to customers prior to purchase.” This shouldn’t really change anything in terms of mechanics, but for gamers who prefer to know whether or not their money will be wasted on something that has a 0.001% chance of spawning will probably go a long way.
Ultimately it could affect developers who might make less money from in-app purchases, but we guess we’ll have to wait and see.