I assume if the cryovac is not tight then it's been ruptured in some fashion and there is air in there so it can't be wet aged. Or it was not properly packed and got out anyway so can't wet age. If it suddenly looks different when aging assume the same.
Cryovac does not eliminate air but if done right (commercially) it limits the amount of air. Air is needed for the aging process but only in miniscule amounts.
When you get a brisket with loose packaging you may also find it's more pliable and you already get a nice bend. that's because of air in there and maybe 3 weeks of time since packing.
Owner/Head Cook/Chief Bottle Washer for Great Lakes BBQ & Feed Competition BBQ Team
FBA Member, KCBS Member & KCBS Certified BBQ Judge
Spicewine medium, weber kettle, gas grill