I'm all about that morostide zapper, so when I went to check what new skin I was lucky enough to get I realized that none of my skins for the mysterious vials were available, even though I know I tried out at least two. Do I have to drink the vials again to unlock those skins?

They only unlock if you drink them during Survival (starting this year), unfortunately.

Thank goodness I hoarded a bunch in my vault!

That's just how I feel about it! XD I haven't unlocked any yet either.