Halloween has the most discarded plots in the history of horror series
H1 was going to end with Micheal Myers officially dead after taking 5-6 bullets and falling off that balcony
H2 was going to be the official ending to the series and was going to be sequel-proof
H3 had nothing to do with Micheal Myers and future sequels were going to be contemporary as well
H4 had an ending that was abandoned since Friday The 13th, Part 5 did the same exact thing
H5 had a cliffhanger that took 6 years to resolve and the Myers house was a mansion instead of a house (WTF!?)
H6 ended with Loomis either dying or being cursed and was later written out of canon with H20
H20 tried to reboot the series and ignore H4-6 and have yet another sequel-proof ending
HR discarded the ending to H20 and was left open for another sequel, which we never got
RZH1 was a reboot, in which Rob Zombie gave us a crappy trailer trash version of the original
RZH2 ignored some of the continuity from RZH1 like the mother's suicide and both endings were just awful
I heard that Halloween Returns will now ignore both the H4-6 and H20-R timelines and pick up 18 years after, setting it in 1996, one year after H6, had it followed that timeline.