I have a low level wizard I was going to level up and select the PrC Magaambya Arcanist for him when he could. I just looked and saw that PrC is no longer PFS valid. SO i figured since he was not lvl 2 yet I would switch him to the Magaambya Arcanist archetype for the Arcanist class. I now see that that archetype is no longer PFS valid. When did these changes take place and for what reason if anyone knows. Many thanks.
Magaambyan Arcanist looks fine to me.
Pathfinder Campaign Setting: Paths of Prestige **
Prestige Classes: Aldori Swordlord, Bellflower Tiller, Brother of the Seal, Champion of Irori, Dawnflower Dissident, Golden Legionnaire, Green Faith Acolyte, Hellknight Signifier, Knight of Ozem, Lantern Bearer, Magaambyan Arcanist, Mammoth Rider, Prophet of Kalistrade, Riftwarden, Shieldmarshal, Skyseeker, Sleepless Detective, Storm Kindler, Tattooed Mystic, Veiled Illusionist and Winter Witch are legal for play.
I am guessing that you are checking with Archives of Nethys. The reason that those are showing as not legal there is because they are reprinted, and maybe updated, in a hardcover book that is not yet included in Additional Resources.
No problem with the Initiate, either.
Pathfinder Player Companion: Arcane Anthology
Archetypes: All archetypes in this book are legal for play except the deep marshal. The eldritch scoundrel is not available for use with the unchained rogue:
...
However, its entirely possible that the Magaambyan Arcanist in Paths of Prestige may be retired when the Additional Resources for the Adventurer's Guide is updated. Existing characters may or may not be grandfathered in if that happens.
According to this thread the Initiate is unchanged, and the Arcanist only got a minor clarification to one ability. So I suspect that the new versions will be legal, and that grandfathering won't be an issue.
OK. Many thanks to you all for the responses.