I just noticed that on the Tesla page today. Looking here for any more info, but that new Royal Farms location would be key, easy on/off going West, a short drive for those heading East, but not too far out of the way.
My only hesitation with that location is that is has had recurring massive sinkholes on that site for several decades. I can't believe anyone would build anything there. I'm hoping they've figured out the cause and have done some amazing engineering to permanently resolve the issue.
Please post with any new information on the official spot of the second Frederick supercharger!