C.YW 😉
Indeed, connecting something labelled "NC" to ... well, anything ... will, under ideal conditions, do nothing. Under more realistic conditions you can expect misbehaviour or worse, up to and including releasing the magic smoke in a violent manner.
If the manufacturer wants you to tie unused pins to ground, or Vcc, or something else, they'll tell you explicitly in the datasheet. They definitely won't label them "NC" ... in a correct datasheet, anyways.