It's pretty much of no consequence. The way I see it, the only reason he's going to be there is to introduce the new guy, since the new guy needs him in order to be introduced. Scott Lang needed Hank Pym to take over the Ant-Man mantle and John Stewart needs Hal Jordan to take over as the next Green Lantern of Earth. Another thing is the "legacy" concept doesn't necessarily work the same way in movies that it does in comics. In the comics Hal is still going to be a young guy no matter how many Earth Lanterns come after him, same way Batman is still young, despite raising four Robins. That won't be the case while taking the cinematic approach to legacy. So I could probably live with Hal being the second fiddle as long as he's better portrayed than he was before.