If they played offense, then yeah. It's not unrealistic to say that the defense looks like it's in good shape. There's uncertainty there, too, but less. There's more talent for sure, and if Mayo knows anything, it's defense.
But as we've seen, an above average defense, even an elite defense, won't score a lot of points. If they turn out to be well above average or elite, the defense will win some games for us, and if you say they might be elite, I won't say you're crazy.
The offense is a different story. Big personnel changes, new coaching, an OL without an established LT and questionable talent at other positions, a rookie QB that may or may not play based on his uncertain development and the team's appetite for risk. If you tell me they are going to be average, I'd say there *might* be a chance, but everything would have to go right: the OL gels, Brissette has a good year, we hit on our WRs, Mayo can coach offense too (he might not be calling plays but certainly he'll be in on strategy and key game decisions), etc. If Maye figures things out and looks so good they figure they have to start him, that might change everything. But that's not likely.
tl;dr Judon & Gonzo make the defense better, but there's so much uncertainty regarding the offense, there's no reason right now to believe they are better than Vegas says they are.