Terry, you are correct that that the "official" Tour Divide page isn't updated. It does give the basic rules and regulations for the race but that's about it. Racers use Spot trackers through Scott Morris's
www.Trackleaders.com website. He usually shares a link here or on one of the Facebook groups so one can register their spot or rent one for the race.
The official GPX is also shared by Scott. His website is
www.Topofusion.com . Most people use Garmin Etrex 20 or 30's. Which software to use is up to you. The better your best map the more info you'll have at your disposal. For paper maps you can purchase the route from Adventure Cycling Association. It varies some from the race route.
I put together a detailed guide to the Tour Divide and other routes. You can check it out
https://oneofsevenproject.com/tour-divide-resource/. I did my best to pull all the information I could into one place.