Hi there!
There is a subcategory on the forum for requesting features or changes. #self-service:wishlist
UFO’s is one that has been requested. Please contribute to this topic and cast your votes there.
AI UFOs & Military Aircraft - Self-Service / Wishlist - Microsoft Flight Simulator Forums
Before posting in the #self-service:wishlist subcategory, search to see if there is a current topic as we only want one topic per “wish”. If your wish isn’t there, then create a new topic. You may want to browse the wish list for anything you like and up vote it. Those that have the highest votes are brought up to the developers.
So that contributions are not split, I’ll close your topic.
Thank you!