Should vacuum sealed food be exposed to air when thawing?
Members of the Genus Salmonella are facultative anaerobes. That means they'll grow in both air and in what you bag sealer calls a vacuum.*
I'd just leave the bag sealed, unless you want to check it for smell before cooking. That could be informative.



*Not putting down your bag sealer. They just don't pull a lot of vacuum. You've probably got half a psi or more in the bag when its done, plus air diffuses into even 5mil freezer bags over time.