I know there are limiting factors (cast unable to reunite, money, slots, etc.), but shows that were part of the current season should get first shot. Only if the pass should outside performers be considered.
Performances of closed flops really are not that beneficial to anyone other than finicky musical theatre fans. Just as with the performances of currently-running nominated shows are to increase public interest and hopefully generate ticket sales, preview performances of upcoming Broadway shows serve the same purpose and make more sense. I would have loved to have seen Kelli O'Hara perform something from Bridges, but I understand why it didn't happen and that my personal interest in seeing that performance makes absolutely no sense from the perspective of the awards show producers.
The Music Man rap thing was just a another dumb effort at making Broadway appeal to a broader demographic, but that was really just a specialty bit, not an actual "performance".
What I don't miss are the classic hit medleys performed by a group of hosts resembling a school talent show like in the early 80s. God, those were painful.
"What can you expect from a bunch of seitan worshippers?" - Reginald Tresilian