Parachutist forbids it, but while combat jump does have many minor restrictions, being in the enemy deployment zone is not one of them. A quick glance through of every instance of deployment zone also reveals that firefight lifts prohibitions on dropping into the enemy deployment zone, but I cannot find the rule that says you cannot in the first place. Sorry if this has already been addressed elsewhere or if I have overlooked something.
There is no restriction to combat jump when it comes to the enemy deployment zone. It would be stated as you've seen with Parachutist. Since 1st edition combat jump has never had restrictions against it when it comes to landing in the enemy deployment zone. It's a skill that is intended to be used to do so but you'll need a successful PH roll to accomplish it.
Note that in N3 it was only a restriction for Combat Jump if you failed the PH Roll and ended up in the enemy DZ. With the removal of Dispersion, that can’t happen any more.
