I think it's a loopy system, and I certainly was unaware of it, not having flown UA for 15 years, and never having had status with them.
What happens if the 'status' pax don't want the salmon, but rather whatever the non-status pax have ordered (because they couldn't order the salmon). Does the FA return to pax and say, "well, actually, you can have the salmon, and you can't have the dish I 'forced' you to order because I now want it for the status pax in 5A (whose salmon you now can - indeed will - have)"?
Frankly, when you're in the same cabin, you should have the same menu, no matter whether you're UA's highest status pax on a full fare, or non-status on a miles redemption flight.
If you're going to employ such a silly system, then at least have different menus for status and non-status pax, or take orders from status pax first and then advise other pax what is still available. And even that sounds silly.
Dumb as cough!