Blizzard is (so far) removing the ability to have gear management addons such as Outfitter in patch 3.3 and you will only be able to use the built-in Equipment Manager. Blizzard could still revert that change, but that’s the way they have it right now on the test realm for patch 3.3 and I haven’t seen comments from them saying that it’s an accident. This change appears to be in response to addons which allow rogues to stack higher-than-normal numbers of poisons automatically during combat.
Players should consider moving their important outfits over to the EM by clicking the W icon next to those outfits in the Outfitter UI. That will copy them to the EM so that you won’t lose them once the patch is released.