I think Gilbert is pretty overrated TBH. He will be a top 10 LW in the UFC but I doubt he'll ever contend for the title if he doesn't receive an immediate title shot upon entering the UFC.
He won't fight Nate, can't see him beating Pettis, Maynard or Jim Miller. Cerrone is a toss up.
He could lose if he gets matched up with guys like Nurmagomedov, Lauzon, TJ Grant, Dos Anjos, even Tibau and Volkmann and it's not as if the majority of MMA fans really know much about those guys (aside from Lauzon), so a loss to any of those guys would really damage Gilbert's career and the likelihood if him losing to these guys really isn't as small as some may think.