It seems like there are contradictory rules, and FIFA is confused about which to apply.

5 days ago, FIFA said there was no appeal process. Yesterday, there was a magic reversal.

No, those are not at all contradictory, it is entirely consistent.

Two things can be true at the same time:

1. There is no appeals process that USA (or any team) can initiate

2. There is a mechanism that FIFA can initiate to suspend a match ban at their discretion

That is why it's a bad system; as long as it's initiated by FIFA, it will always be arbitrary and capricious.