Yes, cyberzombies gain immunity to normal weapons, with their negative Essence being used instead of Force. This is extra bad for anyone fighting them. Their astral hazing will often disrupt things such as killing hands or weapon foci, which would normally negate immunity to normal weapons. And since cyberzombies have boosted augmented Attribute maximums and are typically crammed full of deltaware, they will usually have lots of implanted and worn armor on top of that immunity to normal weapons.
Personally, I think immunity to normal weapons is too broad of a power. A lot of non-magical weapons have forms of attack (fire, sonics, etc.) that I feel would fall under different categories of immunity. I personally think it should only work against non-magical physical attacks such as blades, bullets, etc. and not apply to things such as electricity or acid. Purely by RAW, though, it works against any attack that is not explicitly magical.