I disagree with that take. Yes, he was smiling, but it was coyly, politely smilling, not sarcastically.
We tend to avoid saying things bluntly in Senegal, especially important things.
He was asked a sensitive question. And instead of swerving it, he decided to answer, and did so with the culturally appropriate amount of humility signaling and formal indirectness, reserved for important things. He casted it as something of a shared outlook, not simply emanating from his ego, and closed out with a formal saying/maxim about not talking too much about better things soon to materialize.
So, yes, his answer was coy and smily, but it very definitive.