Originally Posted by Qwkynuf

This is actually not accurate, based on my recent experience. I definitely used an RUC 2 weeks ago as a Platinum to upgrade to the front on an overnight nonstop flight from LAX to JFK. My upgrade didn't clear until 30 minutes before departure (10 minutes after boarding began), so it was pretty stressful waiting to see if I got it, but i got it.

Also, I am about 99% certain that the only flights on this route that are Medallion Upgrade restricted are the nonstops with the "Delta One" front cabins - the ones with the lay-flat seats. Flights with a connection are eligible for upgrades.