Taking a brief look at the CBA (so don't weigh this too heavily), it looks like discipline for off-ice conduct is far more a matter of the commissioner's discretion than for on-ice conduct. For on-ice conduct, a player may be fined or suspended for a fixed number of games. For off-ice conduct, a player may be fined, be suspended or expelled from the league for an indefinite or definite period, or have their SPC cancelled. Suspensions do not necessarily have to be for a fixed number of games (even though this one is being described as such) and may be through a certain date.
Anyway, this all seems like kind of a moot point to me. Obviously the parties here knew this was coming, since there was a league investigation and the player has a right to a hearing prior to discipline being imposed. If Pinto had needed to be under contract for the suspension to go into effect, then it would have been in both his interest and the Senators' interest for him to already be under contract. Also under such circumstances, it would have been in the league's interest to expedite proceedings to prevent Pinto from taking the ice for the Senators while discipline was pending against him. Either way, it doesn't really make any difference to Ottawa's cap outlook as it stands now.