Not at all.
Enemies have been popping out of thin air in VT2 since day 1, and they still are.
You can watch it in this very thread.
Mauler popping in on the left side
Marauder spawns behind teammate infront of them
beastmen group spawning near tree
Rat ogre spawn
ratling spawn in the brief moment everyone looked away
Mauler spawn left side on the edge of the screen
Marauder spawning behind cart
Enemies spawning complaint
beastmen spawning
Stormvermin patrol spawning
Clan rats spawning
Beastmen banner group spawning
Packrat spawning