I could think of many situations, however, where the objectives should be unclear.
Out of curiosity I let an ALiVE game run several hours that only had non-overlapping TAOR's and no syncing of modules, on the Zargabad map using NATO vs. FIA. I then put it on 4x speed. Some combat must have happened because when I came back to it, all the insurgent profiles were gone and the Blufor were all camped out at base.
I have encountered situations with my Unsung missions where insurgents (VC) will enter blacklisted areas such as bases to plant mines and punji sticks, if their TAOR is close enough and they aren't shot first. But they never spawn in blacklisted areas.