You shouldn't be able to get a trademark on "Threads," any more than you should be able to get a trademark on "Doors" if you owned a company that sold doors called Doors. "Doors.com," fine; "Doors.net," fine, "The Great ...doors," fine. Facebook will protect Threads with trademarked logos and color schemes, not by pretending that they own the concept of threads.

Also, if you want to name your car company "Threads" or even your clothing company "Threads," fine. If you want to name your thread company Threads, you can't have a trademarked word.