Is he? Just fairly easily outfought a former champion after all and beat Phil Davis directly before that.
I've lost a bit of faith in Gus after the Cormier fight personally. Don't think he's really improved in the last couple of years and was making some odd in-round decisions like constantly looking back at his corner. He looked at his best against Jones and the UFC desperately wants to make that rematch.
Gatekeeper or not Bader's won 5 fights in a row and that's far more than anyone else in the division bar Jones. Unlike Johnson he's not been getting obviously favourable matchups like Manuwa either. Though decision after decision is pretty damn boring. Hell, even if he does get slaughtered in a title-shot it just adds shine to the champ (almost definitely Jones) with a clear win. Sure, it may not do huge PPV numbers but Rousey - Correria showed fairly well that a good squash match can sell well if it's hyped the right way.
Bader on has definitely improved his boxing and isn't making as many dumb decisions like the one that got him ko-ed by Machida (as far as I remember he basically didn't like getting boo-ed and tried to bum rush a lethal counterstriker) or submitted by Ortiz. He also appears to be carrying less muscle into the cage, so may be having easier weight cuts and be better hydrated which could explain why he's not been as chinny as in previous fights.
Don't think he beats Cormier or Jones, but I think with a good gameplan and movement he can possibly get past Johnson.