Yeah, I doubt it will be built quite that soon. I'm curious which direction you're coming from and heading toward? Always along 75 or 40? If on 40, it looks like a Pilot Travel Center near Waynesville is getting a DC fast charger (CCS and Chademo) soon. That could be a nice backup option for people with a Chademo adapter or if Tesla ever releases a CCS1 adapter.
I would have personally preferred if they put the supercharger in Gatlinburg since that's where I always stay vs. Pigeon Forge, but I understand why Pigeon Forge makes more sense for Tesla. Pigeon Forge vs. the existing "Knoxville" charger will cut the time to get a full charge from Gatlinburg down from at least 2.5-3 hours down to 1-1.5. For me, that's the difference between my wife being ok with taking a Tesla on that trip vs. taking an ICE car/hybrid.
Coming from north Atlanta metro (and not off I-75 corridor), I have always gotten to that area via 985 and through Franklin and Cherokee. It's a MUCH more pleasant drive than I-75. It's prettier, there are far fewer semi trucks, and you can avoid the disaster that is Chattanooga traffic. There's a huge wasteland of superchargers, or even DC fast chargers generally, in that area north of Atlanta and between Chattanooga and Asheville, but it's a pretty popular area for vacations and most in that area will not have slow charging available to them at night.
I'm also frequently heading to or from Asheville via the Blue Ridge Parkway. Having to drive from Gatlinburg all the way to Knoxville to charge up before heading south from Gatlinburg just simply isn't a viable option. Until there are more slow charging options in Gatlinburg itself, there's a big need for a supercharger in Sevier County. There's also, IMO, a need for one somewhere in one of Franklin-Dillsboro-Cherokee-Bryson City. Franklin, IMO makes the most sense but any of that area would probably work just fine.
Rivian specifically mentioned the Blue Ridge Parkway as an area of emphasis for their RAN. I wonder if Tesla will try to match that to negate the selling point for Rivian. The RAN map looks like it's got a fast charger in or near Nantahala Gorge, 1 on each side of 441 through GSMNP, 1 in Asheville, and 1 in Boone-Blowing Rock area. With Pigeon Forge getting a Tesla supercharger, they could probably get away with just 1 south of GSMNP and 1 in Boone-Blowing Rock to completely eliminate the possible RAN advantage in the southern half of the BRP. Nantahala Gorge is probably a little more "adventure" oriented than Tesla needs to worry about.
EDIT: I also meant to ask if you knew of any slow chargers in Gatlinburg that might work as well. The Blink station at Bennett's seems to be the only one actually in downtown Gatlinburg. It does seem fairly reliable, but might be prone to ICE'ing. Unfortunately, the stations at the two GSMNP visitor centers are always down. Sometimes the AC charger will work, but the one at Oconaluftee seems to get ICE'd somewhat frequently during high season, from what I've seen driving by.