It is a long time since I played SH3 so I cant be sure, but the new version will have this structure:-
Campaign Area
Each of the 12 campaigns will be set in an area (theater of war). These theaters will be large areas like North Atlantic, South Atlantic, US coast, UK coast, Med and even the Indian Ocean. Within these theaters will be Objective Areas.
Objective Area
This will form the main part of the campaign and is related to the war needs.
The area will be large for the most part and any kills here will count towards the campaign goal.
It will end by date (mostly many months ranging from 2 to 10) or success (enough kills to achieve the campaign goal)
Patrols in these areas will be for the player to choose or can select areas from BtU. If selected from BtU they will be issued a patrol area within the Objective Area.
The player can do as many patrols in this Objective Area as they like and can return from patrol any time. Most patrols will end due to player running out of ammo or low in fuel. If area is a large distance from their base - milkcows may be used to resupply if available.
Patrol Area
If player has requested these from BtU - they will be given an area to patrol within the objective area.
This patrol area will last for one patrol only and may be cut short or extended by radio message from BtU. These areas will be smaller than the objective areas and may be moved also by radio message from BtU.
BtU will also remind the player that they should always make the final decision on where to patrol to acheive the most kills
So as you can see - there will be a lot of freedom to achieve the war goals as you see fit. There are no penalties for not going to a patrol area.