I think you could say neither Thatch (with his vicious KO of Thiago) & Gastelum with his win today over a fringe top 10 guy in Story are prospects anymore because they are right there as well. This division is awesome now.
Plus if GSP ever comes back (if he gets acting roles like he did in Captain America who knows if he does...) you got an instant PPV draw again.
Edit: I forgot guys like Ryan LaFlare & Stephen Thompson as well. Thompson especially. He's looked much better in his last couple fights.