As FB plat I received an OPUP earlier this year at the gate, while flying HKG-PVG.
However I very seriously doubt it had to do anything with my plat.... I'm quite sure it was related to an overbooked plane instead.

With around 60 MU flights in the past 12 months I already feel "upgraded " if I manage to get a seat in the front instead of a middle seat in the last row

So don't put up your expectations too high..... It's MU we are talking about!