With Iwata's passing, Miyamoto is acting as co-CEO with Takeda. Naturally, this could make Miyamoto a much more busy man -- meaning he wouldn't have as much time to focus on Star Fox -- meaning the game could ultimately be delayed. He's also already deeply involved with the theme park @ Universal.

Personally, I'd like to see Nintendo take the task of appointing a new CEO carefully -- but I also would like SF: Zero hit before Christmas.

We may yet see Hashimoto from Platinum completely take over directing Star Fox Zero -- which wouldn't be so bad as he was the director for Bayonetta 2. 

I doubt it. The game doesn't even look like its that big of a project to be delayed without miyamoto. Plus I m sure miyamoto would have told them enough by now for them to complete the rest on their own since plat is more than a capable developer

I can't really see it being delayed. That's basically ready to go at this point minus a few tweaks here and there.

I would like them to actually delay the game if it allows them to add different controls schemes, multiplayers mode including online and maybe alos improve the visuals (althought they might be doing this already since the non playable desert level looked great!).

Star Fox Zero looks like it was built in someone's basement. I doubt this will delay such a meager-looking project.

No.

If the game is set to release this December, development is probably already nearing completion. I doubt much more needs to be done to complete the project on a content level. Cleaning up and refining the art and gameplay aspects is something that can be done without Miyamoto's direct supervision.

Was he programming it himself?

lol no...newsflash! People die.

tbh i rather they delayed it and added some real depth and replay value to the game.

atm it looks like a small project of an upscaled starfox 64 with some wii u tablet controls experimented.