This is not something that occurs on DL. I concur with what many have written here and the only times you'll see DL people upfront is:
1) If they are execs.
2) If they are deadheading or responding to an "emergency" (I put emergency in quotes because it can be as simple as two many people calling in sick at a certain station, or some kinds of super-delays at a nearby station)
3) They buy their own tickets and believe it or not are actually also Medallions (I personally know DL employees that are FO and GM, because they need to make sure they get certain places at certain times and do not want to deal with the hassles of standing by, especially when they know the flights to be full).
Again, Dl does not have this problem, UA on the other hand is another story.