I am concerned about this Delta thing mentioned above.

It is as if the new flight that the OP would be put on was not one that had any award seats left on it so some idiot decided to use that as a way to conform to policy in a case where what had happened should have obviously overridden any such rules. ie, if you try to book an award ticket on a plane that has no more awards available, you cannot get that flight so you must pick another. If the flight you are on gets in trouble and they try to put you on one of those non-award seat flights, that should STILL not be your problem.

I am scared that somehow some way this snafu--if it did in fact happen the way I am guessing--will continue. (I have no idea what happened of course)
This is precisely why there needs to be a passenger bill of rights. And it needs to cover such minutia.