Don't thank him too quickly. A weaker peso will almost certainly mean higher local prices due to inflation. It will most likely even out or have a negative gain.
There's two statements. That he's poor, and he's defending the poor.
He's not poor. Just his official government salary from being mayor and now president puts him solidly at at least middle class.
You could argue that he doesn't look down on the poor considering that's where he got his vote from. He got voted in as an outsider rather than being part of an elite dynasty.