Yes, I have an opinion. First I dont have a lot of experience with mail in queens but I have a little. I bought 4 in Late Fall my first season, really almost too late for such. (Had a good reason and another story) But each were skinny. I presumed from being deprived from the ability to lay, just as a good ole mated proven queen will be and become skinny just before she swarms; affording her the ability to fly.
It was too late in the season for the queens to mate if they had been virgins to do any good and there were not drones, yet early enough to produce enough bees for the Winter since they were already mated.
I followed the instruction of David, the guy I bought the queens from who is in Georgia. The queens were once again plump and laying again in no time. Following Davids instructions, not only did each Nuc at the helm of these queens survive the Winter, they thrived.
I think these skinny (mated) queens are another good reason to leave the caged queen inside the new hive home, not releasing them immediately , because they can fly away if release immediately. Personally I think it good practice to leave caged queens in the new hive at least 2 days. (just for good measure) Then if she has not been released by then, (by the bees eating away the candied stopper at one end of the cage), being inpatient, I went ahead and released myself. By then she knows she's home and the bees have become accustomed to her and accepte as the new mama... Or you can be patient and the bees will release her.