They took it out because they are money grabbing idiots... When HoW released they said they had an arena that was different every time you play... We all know that is not true, they said they had atleast 20 new modifiers... We have seen maybe 8... When ttk releases you will probably see those scout rifles and they werent even worth the waiting. But because i still sort of like the game i hope that they say somewhere at the end of juli/beginning of august that those scouts are available.

They replace the Vesta Dynasty with the Vestian Dynasty.

They didn't replace anything except the description. The 347 Vesta Dynasty and Fate Of All Fools are coming out with the future dlc, it's been confirmed by Luke Smith himself in a video. You can actually see it in the armory in Bungie.net (They seem to have added the gun in the armory a few days ago)