So basically are you asking for a way to tell if a certain flight is more likely than others to be rescheduled? Even so, it's not likely for routes like AMS-SFO to experience a massive change that warrant UA to waive cancel/redeposit fees.

I suggest you to assume you will have to pay this fee and prepare to be pleasantly surprised if UA makes above-said massive schedule change that forces them to waive fees.

P.S.: For what its worth, I think it's not a bad idea to offer ways to do this systematically via rules (if a non-rev pax goes pax on the same flight, redeposit fees waived), but i am unaware such a policy exists today.