I think it's 50:50 because the cucumbers that do form have a chance to grow and develop.
In the past, my plants got so crowded that a lot of the baby cukes "died at birth"........ so I expect a bit of pruning means you get the same amount of cukes because they all develop well.
I have done all mine and they look so much better. More space to stretch out and less room for things getting all fetid underneath :-)