Lack of a device, but inclusion of the 3-bar, would indicate it's still tuned.
No device though can be somewhat problematic. Especially since that would be indicative of which tuner's tune is still on it.
The presence of an LMS branded CAI is not proof enough of which tuner's tune is in use.
Could be dicey only in the aspect since the lack of a device, as well as the presence of the 3bar MapV Sensor, would equate with no availability to re-download the stock tune file.
Plenty of reputable tuners out there. The most common being Livernois Motorsports based out of Michigan, and Unleashed Tuning based out of Florida.
The fact the car is (still) tuned is not really the issue here, as this platform has proven itself over and over to take incredibly well to a tune alone, and still provide plenty of dependability, as well as long term durability. But no access to the stock tune file is of concern.
I suppose if you're really bent on acquiring this particular SHO, you could, as a pre-purchase investigation, get the VIN, and maybe contact either, or both of the above mentioned tuners, and see if either can verify they have said VIN in their database(s) as having been provided with a tune file.
Armed with that info, you can purchase the appropriate tuning device and then go from there (LMS uses their own proprietary device and Unleashed uses SCT). Both tuners do have stock tune files as far as I am aware of, but getting the right device, and being able to transition between tune file(s) would be beneficial to your ownership.
Good luck.