I assume Apple will go well out of their way to plug whatever hole allowed this boot to happen on new generations.

That's probably not really a concern, since I'm guessing the main thing that enables this is jailbreak, which is an ongoing cat & m game since the iphone 3g's era.

I wish it would be a stepping stone. But be realistic. It's a fun project, a great proof it's kinda possible, but that's all we ever will hear about it. The moment every driver for every lil shit in this device would be remade or disassembled, noone would use this stoneage-device anymore. Or could even get one to begin with.

And as you said, should this ever be more of a proof-of-concept, apple will fix any hole and everything dies.