DL policy is typically upgrading medallion/high fare rev pax to bizelite and seating OAL's in coach. It more noticeable now, so I assume there have been instructions to that effect.
I see a lot more of this, whereas in the past it was all nonrevs up front if open. I'll be happy to ck seat avail on DL if I'm able to access info (who knows where I'll be in Nov??)