Of course they should (provided they are the most qualified and are capable managers).  No one is saying they shouldn't.  In fact, that might free up some positions for the GenXers to hire some millennials.  I think everyone can agree that's a good thing.  But the reality of the demographics is that there just aren't enough GenXers to fill all of those Boomer positions. Without skilled, trained, and experienced millennials coming coming up behind the GenXers to fill the gaps, it's the GenXers who are being set up to fail when they do finally step into the leadership roles.