Theory:

The new netherscape virtual hell is damn close to the library's computer where river song ended up. When she "deleted" herself at the end of series 7, did she just transfer to the new computer. So if the doctor can get Danny back, does he also get River as well??

and of course as River lies, maybe missy isn't the master after all?? but river instead.

"Spoilers"

The Nethersphere is Time Lord technology. The Library was comissioned by humans. The only real similarity is they both contain a virtual world. There is no reason to suggest that River had any knowledge of the Nethersphere, as she was not herself a Time Lord.

There is also nothing to suggest that couldn't happen, but the likelihood is slim.

Also, I sincerely doubt River would pretend to be one of the Doctor's most mortal enemies. Even when she was trying to kill him she was doing it on her own terms... Not sure why you'd think that would be a good thing!