Yes, it is a safety measure to nurture the community.
There are members who just try to promote one brand without ever contributing to the other aspects of the "community"; they never share their experience or document some technical findings. They use the forum as a promote just one thing and then there are some who will try to muddy someone else's thread.
Recently, there was someone who was trying to sell a very nice BionX bike at a very reasonable price, and one irresponsible member was trying to cause a lot of trouble. What this does is create a hostile environment where newcomers would hesitate to share and slowly EBR would lose its reputation or credibility. So, this new rule would help minimize such situations.