You'd bet against him. So would I. And this is even after my eyes were really opened in that Mendes fight. That was when I realized that at 145 (probably even 155) that whatever defensive holes he has don't matter that much at this point because his chin is so damn good. He's just not going to lose striking matches at LW or below imo.
All that said he's talking about WW. And he has the mindset to try to do it (which is awesome, makes him even more compelling). He'd just have no answer for Maia imo if that fight were made. Probably (in a different way of course) Wonderboy too. Of course I'd be on the edge of my seat watching him try, but at some point everyone has limitations.
Unless you were saying you'd never bet against him just due to fandom. Which is cool, I can understand that. I have a REALLY hard time betting against Mir. I have literally been a fan of his since he entered the UFC way back when. I've bet against him, but man did I feel dirty doing it.