I have 2 wp horses that are shown with roached manes. Some halter people who bring home world champions encouraged me to do it years ago :)
I don't know about forlock, but I know you're supposed to leave some over the wither to be in accordance with the AQHA rule book. Why? I don't know.
I just got sick of manes that looked like a beginner banded them when I'm good at banding ;) These two horses are ridiculously thick and one has a cowlick halfway down.
I'd be really happy if the trend shifted to hunters as well :-D