[Number 3]

To simplify the OPs question, they will do what they have already planned to do. Anything major including powertrain changes take several years. GM, in an effort to stay relevant, showed the Gen 6 very early. Ford had already showed the GT, GT350 and GT350R when you can't even get those until late this year and late next year (GT). So Ford has already shown us what it will be doing. The last card for them will be the GT500 replacement. And keep in mind Ford will now have a $500,000 car that the Mustang will never beat. So it's the old "GM will never let the Camaro out perform the Corvette". Of course equal money and technology, it never would.

Fiat? They likely have more time to respond to the Camaro IF they didn't think they were on a path to a better place. They have to do a couple of difficult things. Down size the Challenger for weight to stay competitive, yet somehow maintain a full size car platform for the Chrysler 300 and Challenger. Now they at least have the volume across multiple models. I don't see FCA without a full size car in their lineup. But this may be why Marchioni (sic?) wants to force a merger with GM. Which is hilarious because the Government tried to force that back in 2009 and GM rejected it.

So Ford we kind of know. Fiat? A lot going on and too soon to tell.

But the Gen6 introduction likely didn't send anyone scurrying back to the drawing boards because it was the worst kept secret that we would get an LT1 powered Alpha based car.

And styling likely didn't do anything to make Ford or FCA rethink anything. Like it or love it, the only reaction would be if FCA was also working on a car that looked to close. That would cause a reaction/delay. And I doubt that is the case.