AO Name : New Malden
Role: N/A
If not at the AO the exact location in base/towns: N/A
Time : N/A
Expected behaviour: Normal arma behaviour
Actual behaviour: At seemingly random points, everyone is totally frozen in place, sometimes with black screen. unable to move, vault or jump etc. Seems to be related to getting out of vehicles, so may be related to the new despawn system? 
Additional information: You are able to check the ctab, inventory etc. Only way to fix this is to respawn. Zeus intervention does not work

So is it random it did it only happen the once when getting out of the MRAP?

It also happened after you left when me, Merman and Alyboy got out of a humvee, but after 10 or so seconds

We have removed the friendly vehicles from the vehicle caching. Hopefully this fixes it.

So does this mean they will now have the old de spawn system?

No

So, from a curiosity perspective, what is the effect of this change?

It means that the vehicles we use won't be cached. Slightly more lag, but it should fix the issue.