It took me a minute to figure out the disconnect here but I got it. I had originally googled for "Tesla findus" to get to the map and the search result actually took me to the LIST of supercharging locations. Ashburn does NOT appear in that list -- OK Ashburn VA does but not Ashburn GA
If I navigate a different way and go to the findus MAP, Ashburn does appear on that. So there's still a glitch in Tesla's public-facing system. Either there's some sort of bug in their data set, or that listing is maintained manually and they just goofed.