They don't show in Adibags or I haven't figured out how to make them show up.

It's not a blizzard bug

Is it a currency or an inventory item? Does it show up in the config panel under Plugins/Currency? (I'm not playing WotLK so can't check.)

https://www.wowhead.com/wotlk/item=40752/emblem-of-heroism#comments

Is is a currency. When you inspect your character details on the right, there's a tab called "Currency" that has additional currency types in it. You can click those and select to show on inventory even without addons.
In the plugins section there's not any option for it.

I looked at the AdiBags source code and it uses C_Currency.GetCurrencyListInfo to get its currency list. So this smells like a Blizzard bug. I looked through my addons to see if any others use it and I see it's used in Altoholic. You might load that and see if it's also missing the Emblem of Heroism.

GetCurrencyListInfo(index) and GetCurrencyListSize() to get the number of available ones.

duplicate of #707