I think it's the other way around.
My belief, at this point, is that Apple's strongly considering (or well on the way to) entering the publishing and production side of just about all content creation, including games.
There's already strong rumours they're making music videos for artists under the Apple Music side of things.
In gaming, I wouldn't be at all surprised if there's funding being granted to teams of larger scale producers, along with specialised builds of Sprite Kit and Scene Kit with focused Apple engineers providing the desired features for them in their custom builds of the engines, and onsite support and guidance... and problem solving.
Consider that the best and brightest of their game engine developers might well be doing this. A brain drain to the upper echelons of the gaming market.
Those offsite productions (they might be onsite, too) are probably using much more advanced versions of the game engines, relatively bug free. However becasue these are all branches and there's probably not anyone left to merge the best and brightest of the branches, their builds and features are not coming back to the public facing versions of Sprite Kit and Scene Kit.
This wouldn't be the first time this sort of thing has happened in the game industry. But it's an entirely new scale of this kind of activity.
Consider it from a greed point of view:
Partner in the production costs, and earn SIGNIFICANTLY more than 30% from a game, and Apple is able to promote any games they're involved with, as they own the store and control its layout and tiering.
Looking at the contents and construction of the new 21 inch iMac, the fact that the new iPad mini has an A8 (not even an A8X) and other interestingly cynical, penny pinching and purely exploitive profitering activities as the default mode of operation is the only correct way to look at the "new" Apple.
Tim Cook mode of operation seems to be "All possible profit, spend goodwill to get at it, too!"
So doing this production partnering activity is a double win for Apple. They get to keep much more of a game's profits (normally these sorts of deals are much like 90% or more to the producer partner) and they get to keep those production teams only making iOS games, not Android, nor cross platform, so they can sell more devices based on more exclusive content.
At this point the exclusive content on the Xbox One is the only thing keeping it somewhere in contention against the superior hardware of the PS4. This sort of thing would not be going unnoticed by those that make strategic decisions. It would teach them that there's true value in exlcusive game content for the platform.
Then take a look at the focus of features in their promotions of Sprite Kit and Scene Kit. It's all about the texture packing for projects that must have ENORMOUS amounts of sprites, and significant In/Out of Models, hence Model I/O. They're focusing on features that are ONLY of benefit to people making games with huge amounts of assets and asset iteration to deal with. That's not the little guys.