[Imp]

I would expect they act exactly as victory hexes always do, if a side owns it at the end you score the points.

Very easy to verify set up a 2 turn battle just buy a platoon for each side.
Place victory hexes on a grey hex & one of your units beside it.
Move that unit onto the victory hex, it will leave the map next turn.
Press end turn till game ends.
Check scores.

As a scenerio designer you could place neutral victory hexes behind a defender to make them retreat to hold them. Placing a few individualy with max points in the grey to cause withdrawl off map.

Fighting withdrawls are surprisingly difficult to do, perhaps because they are a very rare event in this game. Falling back a few hexes with part of your force is an entirely diffrent process to trying to fall back a large distance with all of your force.
PBEM campaign though it can become a very valid tactic, better to survive relativly intact & try again than get decimated & start the next battle in trouble.
That said chasing an organised retreat is also a very difficult thing to do.
Withdrawing is sort of like bounding fire shoot & scoot but while pulling back, some run some fight then swap.
Pre TI smoke is incredibly powerfull, combination of arty dischargers & tanks firing the stuff can turn the tide.
I have changed tactics part way & gone back on the assault after carefull & slightly lucky use of smoke to cut off part of an opponents force.

The variety of units & situations you can encounter are what make this game so replayable along with the fact the unexpected can & does just happen. Era plays a huge part to well trained troops with accurate modern support vehicles fast reacting arty etc there is a good chance things go to plan if your a major power.
WWll heck you best have a fluid plan because things are almost certainly going to go wrong, lesser accuracy allows for a far larger range of outcomes & lack of unit cohesion mobility etc makes reacting a much slower process.
Sorry drifted off topic but never really thought about this before this game is very good the overall feel you get seems bang on target.
I can pull off an ambush at 1.5K with far more certainty on the outcome in a modern MBT than I can at a few hundred meters in my T-34. Modern well trained troops are also far easier to control & hence get the expected outcome with than lesser trained 3rd world troops, the changes might be subtle but they are actually noticable once you play long enough. Which takes me straight back to what makes this so replayable, changes might be subtle perhaps only your subconcious has noticed them but it weighs up the pros & cons of the situation & then that tank pulls off a kill with a 3% hit chance & your back to figuring out how to save the day.
Heck lets give it just one more go I figured out the tactics for those other games & there now back in their boxes collecting dust but this game keeps giving me new challenges & that is just awesome.