First off, thank you so much for such a thorough response! I think my question was answered. My situation explicitly: I had posted a piece through a publication and then removed it from the publication once I heard that it was preferred for the contest. Then, someone pointed out to me that a different story I had posted and tagged MWC Reentry would’ve been a better fit for MWC Space, and I came to agree with them, so I changed the tag after it had been posted.

I feel confident that my entries will be accepted now, so thanks again for taking the time to answer my questions in such detail.