The biggest knock against Gregg since he took over has been his player selection. That player selection is currently magnified as we are about to start our first world cup in 8 years as a country. In this case its Pefok/Reem/Whoever, and if Qatar doesn't go well, it is pretty easy for everyone to use that as the excuse. With all the talent the USA has there will be pressure on the federation to put someone in place that will maximize that talent.
There will always be people who disagree with who coaches are playing, in every sport. This is no different.
For your odds above I would adjust one thing, and it is based on the culmination of Gregg's entire tenue of roster decisions.
Gregg brings Pefok and makes it out of the group stage. 100% he is back regardless of what happens in the knockout stage.
Gregg doesn't bring Pefok and the USA doesn't make it out of the group stage. 95% chance he is done.