In MP player is different on each computer and on dedicated server it is objNull by default (unless scripted).
When user is joining a dedicated server mission, at the moment of onPlayerConnected the player object is remote to the joining client, as the player unit is created on the server, but once control of the unit is passed to the user moments later, the player objects becomes and remains local to the client.
Anything else you see in other scripts is equivalent and/or redundant. (but you may need to add other conditions too, such as checking hasInterface before initiating that loop)
Of course JIP players may need more than just the player to point at the actual JIP player unit, but that's script/mission-specific.