If it were just a bios fix, why the heck would it take until some time in Q2 to release it?! They must not have a solution yet. I'd guess they discovered this thermal-mgmt related system lock-up bug right before release.
So they're like crap, do we delay the release, like we should?
No, let's just disable thermal management in these parts for now, and ship them. Then we'll investigate and hope there's a non-silicon fix. (Or worse, they know it'll take a respin, and they hope for suckers to buy these first botched parts anyhow.)