I have also heard both sides of this issue. I never heard the don't pull the brush back side until after I had been doing it for 35 years however. I own a bunch of weapons from rifles to shotguns to handguns. I do pull the brush back through all of them. As a matter of fact I got a brush with one of my pistols that came as a part of the deal that does not unscrew. If you push it through you either have to cut it off or you pull it back. It could be part of a conspiracy by the manufacturer to wear the barrel out sooner so you have to buy a new gun but I doubt it.
There may be some validity to the don't do it point and I won't dispute it at all because I can't with any degree of expertise. I will say I pull the brush back through and have for almost 40 years now and all my gun still shoot where I point them and get really really clean.