Just a guess but the fact he was buying multiple packs of some strains makes me think he was no amateur and likely stored them correctly . Still a crapshoot but the odds get a bit evener .
"In a bin of stuff' was how he described storage. They look like they may be only a few years old. But then some seed sellers sit on their product for a while, I can think of one in particular who is fairly new but I only got 1 out of 5 popped. Newguy the finger for you! Never again..
bcs "as my family had already cleared the house out "
so that is just how the op found them not how they were stored. My concern is if they were refrdgerated, then removed and put in that bin then back in a fridge was it done in a way to limit any concerns of condensation creeping in and ruining them