TAG ejection SYSTEM and pilot

As you have noted, the Operator has no skill that allows them to dismount voluntarily.

 

To reinforce the post above, they don't have Pilots, they have Operators who follow the rules laid out in ED/ES.

 

From manned :
Units with this Special Skill have an alternative Troop Profile with the Pilot Special Skill on it.

From pilot :
This Special Skill allows the user to use an alternative Troop Profile.
This Pilot Troop Profile is usable only after the trooper declares a Move Short Skill and specifies he will use it to Dismount his Manned TAG or Vehicle.

So you need the pilot skill to dismount using manned.

Operator have also two profile but it's tied to the use of the evacuation device skill:
ED lvl 2, effect section : Units with this piece of Equipment have two different Troop Profiles, the TAG (or Vehicle) Profile and the TAG Operator Profile.