If you watch the video there's strong evidence that there was a cache on the point.
The player killed it with a Panther and then stuka'd the point. If he didn't have munitions then he could have used Stormtroopers with infiltration to decap it. If he didn't have munitions or manpower then he could have used Breakthrough and de-captured the point with a Panther for 40 fuel almost instantly.
Encirclement can use every single type of resource to support this game winning artillery.
I coordinated the whole thing with a friend who was using the same doctrine. We had infantry and panthers at the cutoffs with breakthrough enabled so destroying the caches was easy. We also had 2 stuka strikes ready; both of us were also ready to pop the actual close the pocket once we had the map cut off.
It takes some coordinated effort to use the ability effectively as has been said but that's standard play in team games