If Courage made it to Adult Swim, then it would be more because of attracting a new audience over the show actually having mature content. Sure, censors are stricter now than during Courage's run, but it's hardly a mature show just because it frightens kids.
The audience that it could attract would be a much better reason. People constantly complain about how the cartoons of their childhood are dead, so airing them at night as opposed to the middle of the day on Cartoon Network would attract these viewers.
But yeah, no, there's like zip, nada, cero chances of it being fully remade.