After two years at Cognitect (pre-nubank), I can say that his talks are more subdued than his usual way of speaking (in slack, at least). He's not as mild-mannered as he appears.
Observing a public figure and expressing concern that their workplace doesn't align with their passions isn't prying into their personal life, or speculating about their mental health. What I'm saying is: NuBank is where hopes and dreams go to die, and corporate life more generally. It's not about being "on" or "off" but about being in an environment one can thrive.
It's a bit distasteful to virtually follow him around and speculate about his mental health.