Meat seasoning sealed...

[92xj]

in it's original packaging unopened is flavorful and useable for _________ weeks/months/years?

As in the seasoning BEFORE being mixed with the meat.

If you buy a premixed breakfast seasoning package from Bob's seasoning and don't use it and throw it in the pantry, unopened.  In your opinion, how long will that seasoning hold it's flavoring to mix with whatever meat in the future?

[Fl0und3rz]

But I have used decade old bullion without much loss of potency. 

Salt lasts forever.  Aromatics losing their punch would be my main concern.  If it's mostly salt, pepper(s), garlic, and onion, I would expect a decade or more of useful life.

Add an O2 absorber packet, before sealing, if you are really concerned.

[vandeman17]

used some the other day that was over a year old, tasted normal to me

[cbond3318]

Infinity