Join Date: Nov 2000
Location: Nashville -Past DL Plat, FO, WN-CP, various hotel programs
Programs: DL-MM, AA, SW w/companion,HiltonDiamond, Hyatt PLat, IHF Plat, Miles and Points Seeker
Posts: 11,405
Requesting an upgrade and getting one are of course two different issues.
Your status being the biggest factor. Next biggest is - Can Delta sell that seat instead.
You may also want to scroll down the page for posts about some upgrades are from Econ to Econ Plus or whatever name it is today.