Title kind of says it all. The algo putting together grps for solo bg blitz doesn’t care about what classes have a healing reduce spell/passive on targets.
Really had a great time my last game where I not only play against uh dk and ele shammies but also not having anyone in my team having MS.
Blitzes are not balanced. They are 80% based on luck.
There are many factors that could help a team and punish one.
Like having Bloodlust, or MS like you said, having a Prot Paladin instead of a Guardian Druid/DH tank, having OP dmg classes and healers, having rogues or not.
It is litterally a bracket based on luck.