Gears of war ultimate edition pre-order skins

 Hello, this is my first community comment. I’m loving the gears games and having lots of fun. I recently installed gears of war: ultimate edition through Xbox gamepass and having a great time but I’ve noticed that there are character skins that are unavailable. Such as the savage theron guard and would love to play as this character but it’s unobtainable. Is there anyway or chance for these characters to be added to be purchasable in the Microsoft store or unlocked though in game challenges or achievements? 

  Sincerely, thank you.

How Wholesome, I love the part where you were having, you really brought tears to my eye with that one