Apple is in for 30% of the take from every single gambling and gacha games, and the take is MASSIVE. They have very strong "incentives" to not have a problem with giving kids gambling games.
I am highly critical of Apple's heavy handed "approval" requirements for apps coupled with not allowing users to sideload, but if they're going to do it anyway ostensibly for protecting the user, the least they could do it is block the clearly exploitative loot-box approach.
But yeah, the (monetization) design of Nintendo’s mobile games is quite disappointing.