Green, in a recent interview, stated that writing an episode of this series is very easy for him, given that he feels extremely attracted to the themes and style treated, but that on the other hand, the various films are subject to a large number of different licenses and rights, making it rather difficult to continue the story so as not to unleash one or more legal battles on the matter. So, starting all over again, as in a sort of reboot, is the simplest choice, both from a creative and a legal point of view. Which is definitely not cheap.
According to what Green said, to exclude most of the narrative now typical of the Halloween franchise (the complete series of which you can find in blue-ray version at this Amazon link), is it was certainly a creative choice, which has greatly simplified things, both in terms of narrative and legality. The director also adds that whenever he has tried to include some extremely dear moments in the production, from an artistic and atmospheric point of view, he has always been ostracized. Doing it all over again, then, is definitely the best solution.
David Gordon Green's Halloween trilogy began in 2018 with Halloween, which serves as a direct sequel to the 1978 film of the same name. The revival series continues. with Halloween Kills, recently released, and is expected to end with Halloween Ends, which is currently scheduled for release on October 14, 2022.
It is not the first time that, for one reason or another, the Halloween series has undergone a "reboot" or some sort of distortion of its canon. We are therefore quite confident that the quality of the franchise will not be affected but, on the contrary, will benefit from a real breath of fresh air.