I'm highly skeptical about this speculative rumor, for two reasons:
1) Hugely expensive and labor-intensive, as Zaku detailed above;
2) Do Netflix streamers really care about picture quality? Wouldn't they just watch the SD original versions of TNG without complaint?
PS I hope I'm wrong, and I'll gladly come back here and eat raw Targ (and I'm a vegetarian!) if the rumor is true.