Many asked for it and here it is: you will no longer need to kill at least one boss to activate that track, so if you don't want to Raid, you won't have to anymore. This is a good change for everyone. The Raid mastery will be hidden for those who haven't killed a boss yet. As for why they didn't do this when the Raid was added? Because the tech of hiding a mastery track wasn't available at the time and they didn't want you to master a track without even visiting Raids. Now that the tech exists (with the Griffon also using it) they will expand it to the Raid track. I think news like this should be available on the the forums too.
Side note: there won't be new mastery tracks for the Path of Fire Raids. Also good change in my opinion. So Arenanet DOES listen.