As far as i know, either the SEC asked them to fold up their circus tents like they claimed they did, or the exchanges are lying through their teeth. I tend to give people the benefit of the doubt.
None of the exchanges specifically said anything about SEC contacting them so we cant just assume they were given an ultimatum. It is more likely in my eyes they finally came to see the legal risks they were undertaking and didn't want to spend the time/resources to make their operations legal/safe from SEC. (its easier to just ignore them and keep collecting them bitcoins from the non-americans)
No, it becomes panama vs some random guy. Please keep in mind that this is IRL & not Equestria, podunk countries try not to piss off the big players. The president of the Panama (republic?), whose name is right on the tip of my tongue, given a choice between pissing off some_random_guy & USA, is likely to pick teh prior.
You do realize that in the real world the US doesn't give two shits about exchanges that operate in other countries. And even if they did they cant just walk over to panama and tell them they have to abide by their rules. Can you imagine how the world would react if the US decided that another countries laws were incorrect and they have to comply?
What would have to happen is the Panamanian government would have to comply willingly, which wont happen if they feel that a company in their country is operating legally. And it is not a contest of who you are pissing off more the US or some guy, it is a matter of being forced to change your countries existing laws to appease to the US. The most the US can do is try to block US users but that will never happen because again they don't give two shits about a legally operating exchange in another country.