Whenever I buy frozen vacuum-sealed fish, the package clearly instructs me not to thaw the fish without removing it from the vacuum seal. This makes sense in a hazy intuitive way if I think about anaerobic bacteria like botulinum.
However, the frozen vacuum-sealed meat I buy has no such warning. For example, Omaha Steaks explicitly suggests thawing meat in the vacuum-sealed packaging.
I can't think of any reason why one would be OK if the other isn't. Is this a regulatory quirk, or is there a genuine reason why the correct thawing procedures are different?