Frostmourne Heirlooms

Hey :) First I would like to say, I'm a "supporter" of Warmane and keep coming back year after year. Thanks for that.

My question is... I just bought a complete set of heirlooms on Frostmourne, what happens to them when the Season is over?

I already have geared toons on Icecrown so transferring would be redundant.

I'm just curious about my heirloom investment. Do I have to buy to replace an additional set for the new Season? Or do you have some sort of BOA Heirloom plan for Frostmourne?

I keyword searched for some time for an answer, finally ended up here.
Thanks in advance.

Edit: I realized that this section of the forum is answered by other players who may be just as stumped as I am. Ill post this question again in a more administrative category.