SirPrimalform: Revoking the keys and offering to replace them is one of the most ridiculous bullshit things I've ever heard of. There's basically no point in doing it at all, apart from being petty.
Presumably the IFK still holds a percentage of unsold codes (they didn't sell 10,000 copies, which is what they ordered the devs to originally supply) so the developer doesn't want them to use said codes in another Steamgifts thing or something. It was Desura, and I don't even think you can revoke a Desura code. I assume this was meant as any unredeemed codes would be rendered void, but if you haven't redeemed your code you can get a new one.
That's the way I took it, anyway. Obviously I'm pretty biased here, because I really do despise the IFK. I do think Biart has done some undeniably shitty behaviour, but I don't believe that it was entirely unprovoked.