>>49553902After Gen 2, yes.
In Gen 1 and very early gens for Blissey would you see them be used as special attackers, since Gen 1 had 105 Special and Blissey is sometimes able to use Calm Mind.
Both are actually seen on offense teams actually, as their utility to prevent something like Mega Charizard Y or Specs Latias from rolling over your frailer teammates.