The fact that they didn't include a question mark at the end of the sentence doesn't change the fact. The correct answer is still "No, Of course not." It's then up to them to decide whether it's worth firing you for giving the sensible answer to their silly request.
Am I missing something or were you involved somehow?
I simply asked a question prompted by this bit:
"Keep in mind that they didn't "tell" you that you'd be on call every night. They asked, and you said OK."
GGP did not suggest in any way that there was a dialogue, he simply said that he was told that he had the bad shift and that was that.
So either JasonKester knows more than is apparent from the comment or I don't understand where he got that knowledge, it's not as if walking out was on the list of viable options for the GGP.
Please indicate why you think I'm hostile, or is asking questions the new hostility?
Repeating though, in case it wasn't clear: When your boss says "Yeah, we're going to need you to come in on Saturday... yeah, we lost some people this week, and now we're gonna have to sorta play catch-up. And yeah, we're going to need you to go ahead and come in on Sunday too". That's a request. It's something you can (and should) say "No" to.
It's entirely possible that there may be ramifications for standing up for yourself in the face of silly demands from management. But there's absolute certainty of bad things happening if you don't. (Namely, the terrible thing you've just been asked to do, as well as dozens of repeat performances now that you've declared yourself as somebody who can be walked over.)
The best course is always to remain professional, stand up for yourself, and ensure that you remain on equal footing with your employer. If they do choose to fire you for working the hours you agreed to work when they hired you, there are worse things than being a skilled developer in the single best market for talent in history.
So I don't see this as a request at all, a request is something that you practically can say yes to, which doesn't appear to be the case here and does not come in the form of an order.
They do indeed have places where an employer can reasonably ask an employee to sacrifice his entire life for the company. Those places are nearly all called "Japan", and the employer/employee relationship is very different to that in the USA.
Try enslaving your workers here (or firing them for refusing to be enslaved), and you face an unpleasant lawsuit.