If you wireless router will allow it, set up a SSID for both 3ghz and 5ghz with different names then only give the steam link access to the 5ghz SSID. I do this to make sure only certain devices can hit 5ghz and has worked out pretty good.
So evidently if you ordered and got the cards, you still have the cards but you can no longer order it if you didn't.
League of Explorers Purchase Issue - Hearthhead News - Hearthstone
I thought they should have been shit canned from the start. Maybe you should upgrade your memory or go read these past years threads I can't remember you posting in.