The hit violates rule 7.6 in the NHL rulebook which is for head contact. Direct head contact is not permitted in the NHL and can be grounds for ejection and further disciplinary action, if the NHL deems necessary.
This is big news as the NHL can not suspend players over 5 games in an online meeting but can in an in-person meeting. This does not necessarily mean that a lengthy suspension will be handed out, but the possibility is there. The NHL will announce the official ruling soon.