Does Darkmoon Faire's specifics items disappear after the event?

I'm currently making a stock of Darkmoon Firewater using the new Darkmoon Fair currency introduced in 6.2 patch, which is Darkmoon Daggermaw.

Will these potions disappear from my inventory/bank after Darkmoon Fair has ended ?

And in a more general way, how can I know if a specific item is linked to a temporary event and will eventually disappear after that ?

Have checked on many sites like wowhead, wowdb .. but didn't found comments mentionning this probable issue.