While I have no idea if this is official UA policy, nor exactly what the order is (or supposed) to be, it happens routinely enough to me that I assumed it was policy. Again, this has only been on UA metal. The few times i've been on a UA codeshare to US, it has not happened, even though the manifest shows my 1K/Chairman's status.

One FA on a recent transcon handed the 1K & GS members a small form asking us to select our preference. Later I asked her what the forms were all about, and she replyed it was "her touch" to make sure we got our meal choice first without having to ask one person in a row their meal choice and skip the other person in the same row.