I just tested with a Soul Mastery pet, and it DID follow me into a different zone. It is most likely that what you're reading is an artifact from when pets didn't zone at all; most of the time, when powers change, the descriptions seem to get forgotten.
I cannot confirm anything for the Mace Mastery pet, but my Summon Widow also has the note saying it won't follow me out of a zone, which is obviously untrue.
@Roderick
Well, looks like you're right. Just an artifact, at least on the test server. Thanks much for the reply.
Yeah, the Devs aren't too keen on updating outdated text descriptions for some reason.
My Blaster's Mace Mastery Spiderlings follow him everywhere until they blow up.
I recently have been looking at respeccing into Mace Mastery. However, after reading the description of the summon, it says that it will not follow me out of zones or missions.
1. Is this true?
2. If so, why? The Mu mastery pet follows out of missions (At least to the best of my knowledge...)