Delta Prefered seats out of control
One thought... If the OP is asking for the four of them to be seated together, at this stage in the game, isn't he requesting that someone else get their seat changed "randomly" reassigned by delta?
Also, think about it. Leisure passengers are far more likely to jump at a voluntary denied boarding opportunity than business pax. I'd wager to guess that even though the mco mem flight was oversold, there would be next to no risk of the op not getting on the flight, regardless of if he had seats selected or not. Future free trip to disney to someone on the flight? Yeah, someone would jump on that and no idb.