Draenic Wildstaff from Auchenai Crypts (BC dungeon) shows missing, but I have learned it from other sources and can use it or transmog. Shared appearances showing other options race locked, but I am pretty sure when you complete quest and get appearance then other races/classes can use it also. I am playing Alliance mage and have all other items from that dungeon. I have I only care about my main option ticked.

Can you turn on the tooltip setting for "Show Shared Appearances" and then provide a screenshot? Depending on which item it is you unlocked could be why, but would need to see more information.

Usually if it's a race / class locked it will not unlock the rest in Unique mode.

Is it an alliance mage or druid you are seeing this on? The image shows druid, but you mention alliance mage. When you are on your druid try to uncheck "I only care about my main" and recheck it (forces a recalculation)

No matter what though your mage more than likely won't be able to see it until you get that specific staff. While one is marked "Race locked" they are both technically "Class Locked" too due to it being a druid only quest.

Quest is for druid only yeah, but when you complete it then you can use those for transmoging mage also. Adding pictures with mage now.

Void Elf Warlock has the staff from Druid-only quest available as tmog variant, since the staff from the druid quest has no Classes: or Race: restrictions on it.
I did the druid quest, I do not have the Burning Crusade dropped version one. Blizz UI is telling me "I have collected it, but not from this item".

I believe the "Race Locked" flag from these druid staves (of the Green Circle, of the Verdant Circle) should be removed from ATT database, as it's currently incorrect.

I've checked archive.org and for at least 6 years wowhead shows this item has not been marked as Race locked:

https://web.archive.org/web/20120725045958/http://www.wowhead.com/item=65461/staff-of-the-green-circle

It shows the quest as race and faction locked, yes, but not the reward.

Just a heads up, don't take what wowhead says as always accurately. They have things incorrectly marked on some things that we have noticed as we input things. Like some items it'll say removed, when you can still look, the reverse, and other things.

This item is an odd one and not sure how to fix it.

The reason is when an item is marked as shared it's because Blizzard flags it as so. It's not anything wee do. So Blizzard is basically saying "You shouldn't be able to mog this". Some people have it pull up in their transmog window, some don't. I'll dive into it some more later and see some things.