It is - thanks! The one thing missing is where the dice came from for the wargamers to pick up on and use. The possibly apocryphal story that I heard was that the polyhedral dice came into the hobby via teachers who were using them to teach probability in their classrooms. And that the first supplier of dice to TSR was an educational supply company.
That's what I've heard as well.
From a wargamer perspective, I didn't use polyhedral dice in wargames back then. I used six sided dice. There didn't seem to be a shortage of those.