"Weightlifting belts reduce muscle activation.
Weightlifting belts also reduce the intensity of muscle activation during a lift. This is part of why you can lift a heavier weight while wearing one. You don't need to work as hard."
Here are a couple of great articles on belts from 70s Big.
These are probably not WFS.
I dont know what the consensus is, but I definitely advocate the use of them. I wear it mine every time I squat or dead lift - even in timed WoDs, if we are going over 300# on the squat or DL, I take the time to belt up, its just smart.