I love that Halloween Ends almost make Halloween III: Season of the Witch, the one movie that isn't supposed to be connected to Michael Myers, canon to the H40 Timeline.
Halloween Ends director David Gordon Green says he wasn't interested in a "final showdown-type brawl" between Laurie Strode and Michael Myers.
www.moviemaker.com
Obviously they would have made films about Michael in-universe based on that logic. I feel Season of the Witch would have made more sense to connect to the Thorn Timeline, because of Mrs. Blankenship, Thorn/Silver Shamrock and the obvious number 3 in the title. Since that one is what would be considered canon in the "Slasherverse" then we already know that films were made about Michael Myers from the Hatchet comics - Hatchet II explicitly states that Jason Voorhees and Leslie Vernon are real killers don't forget.
Silver Shamrock masks also appeared in Halloween Kills with the same logo on them as well.