Non-elites on Y fares get Elite Access (although they should also be on the upgrade list, just at low priority). Elites on coach awards (are supposed to) get Elite Access. Upgrades are sufficiently hard to come by these days that I don't see any problem with there being a bunch of DL elites on a CO flight EWR-SLC, if, like me, they are just choosing on price and schedule. I don't find your story that surprising.