That question has been around for a while and, like so many issues, I find it to be more of a theoretical than experiential issue.
Theoretically, you would need to distinguish between sealed bags on tube and solid-state mics. While keeping the bag open over solid-state mics makes some sense*, on tube mics, a case could be made* to always seal the bag after the mic was on:
the volume of (dryer) air in the body of the mic is greater than the air volume in the head basket.
Therefore, in a sealed environment, excess moisture will tend to be sucked away from the drier body to the more moist head, thereby drying out a moist capsule much more efficiently than through exposure to ambient air in the room.
* in practice, I have not found any different results between sealing and not sealing.
P.S.: I have a sticky that goes a bit more into drying out moist mics and capsules:
https://repforums.prosoundweb.com/index.php/topic,37255.0.html