Since I wasn't sure what you were referring to, I looked it up. Wolfenstein 3D was ported to the iPhone and open sourced, then sometime later was put on the App Store.
No, he's not. He's saying that if id did it it can be legally done.
I'm sure it is a licensing issue. If they had agreements for the models or the sound files they'd have to pay those people. I think doom was released without the original sound files. Perhaps that was quake.
I very much doubt that. Generally, either the publisher or (sometimes) the developer owns it all. In the case of EA, those entities are the same. I can't see EA open-sourcing anything, ever, though.
It was not a licensing issue that prevented id game assets from being released. Carmack wanted to share the technology, the knowledge, so others could learn from it and improve on it. Letting people play doom/quake for free was not the purpose at all.
Are the Wolfenstein graphics and sound files freely available too?
No, the data files are copyright by Id. The game is still for sale, e.g. on the 3D Realms website.