@Mark ********
I think I know what it is and what the reasoning is behind it
It probably has to do with the work permit not being valid for 8 months (which is what you need to get a year-long, multi-entry Non-B.
Many times I've seen people get sent out with only the WP3 (receipt of having applied for a work permit) to get a 90 day single entry Non-B, then come back GET their work permit (which is valid for a year) and then go back and get the year-long, multi-entry Non-B visa.