I don't know if that's true.. I run a volvo and the test to see if the PCV is gone involves running the engine and putting a rubber glove over the oil cap; the glove should be sucked down slightly. If it inflates at all, the PCV system is clogged/nackered!
If you think about it, you want negative pressure (vacuum) inside the crankcase so that the fumes are sucked OUT of the engine. Positive pressure is a bad thing, especially for oil seals, etc!