Yep Red has been doing this, even possible with Magic Lantern raw on the 5D, 7D...etc if I recall. It hasn't caught on in a meaningful way,
Dual gain sensors negate the temporal issues and operate on a similar principal. Two separate sensor read out amplifications captured, then combined to reduce noise. Cameras containing dual gain include the C70, Arri Alexa's, Ursa Mini Pro 4.6k...