Why if I choose to buy a skin boost, Can't I choose which skin?

I'm not sure when they changed it, but I thought it unlocked all skins for that champ for 1 game and you got to choose which skin to pick. I Honestly want my 95 RP back. I didn't want to spend money on my team getting a random good/bad skin or whatever. I wanted to spend money so we can choose what skin we really liked since it's only 1 game. like really? is it cutting into the budgets of riot so hard that we can't choose what skin we want to play with in 1 game???