I don't know if there is a story to it to be honest. AlwaysThere or Themidwestcowboy are the best guys to ask on here, they're both great with info and their opinions are really interesting
I don't think Free was ever seriously considered for Bad, at least in that state of completion as we've heard it. I'd guess it was done between 1985-86. I believe it was a Havenhurst song with the "B Team" (John Barnes, Matt Forger those guys)
Not sure if the song was ever completed or worked on again really but who knows. Mike had a great knack for writing catchy hooks, and songs with the strongest hooks would always draw him back to complete them
I love the song myself, I remember hearing it for the first time with a big smile on my face because it was nice to hear Mike sound happy and care free on a track again. You can almost picture him smiling while recording this