Hum wise, it seems like a questionable design decision.
In the "old days" (as if 5 years was eons ago), plasma TV sets would employ ground on the power cord because of the flyback transformers and high voltage needed to drive the plasma screen, and back panel of the TVs being made of metal to support the weight of the screen. (I've had more than a fair share of ground loop issue with Panasonic plasmas hooked up to sound systems.)
In the early days of LCD TVs, the backlighting was CCFL tubes, which also employed flybacks.
These days it's all LCD TV's using LED backlighting (so-called "LED TVs"). The outer case is all plastic with maybe metal inner frame for structure and wall mount. Current draw is 1A - 2A versus 5A-7A for plasma.
John R.