^Okay, thanks. Maybe the OP misremembered the FX in the original as being more static or simple than they actually were.
There is some
CGI in the remastered TNG. They can remaster and recomposite the original film elements of ship miniatures and the like, but a number of things in the original, like planets, phaser beams, the Crystalline Entity, and such, were created using video effects or early CGI and only exist in low-resolution form. So they did have to be recreated from scratch, and what they did with the planets was similar to what they did in TOS-R: maintaining the same basic aesthetic as the original planets, but with more detail and realism.