Can confirm it's possible even after "first kill of the week". Hurray for garrosh boosting. Got a bow after doing 2x boosts, out of about what, 6 tonight? (JK already have multiple mythic-level bows <.<).
Uh.
One: You can't be fucking serious. As long as the stat is usefull for the spec, you can get it. Doesn't matter if the best stat isn't on it. Still usefull.
Two: Both caster heirlooms are crit+mastery now. The mace was originally spirit+mastery. It's really fucking hard for a caster to get a heirloom weapon that isn't crit+mastery when the only two available are itemised like that.