Is there a way to improve quality for videos with snow/confetti/LCD in background?
Yes this feature exists, but it is not widely used yet.

Texas Instrument developped such solution, called SmartCodec, which looks to be implemented in a Samsung video surveillance system: Megapixel Camera This is a HW based solution, that is for market of video surveillance.

I think it would be implemented in future video codecs HEVC, adopted by many boradcaster, and it's called Region-of-Interest Based Rate Control Scheme
HEVC is already released, and in used today, but this feature really looks new. And it will take months~years for it to be implemented in the encoder on the production house, I guess. Apparently, it is something really new, since a paper about that has been accepted for presentation at the ICIP 2016, which took place in september.