Well in all fairness that makes since I guess. I mean BLM talked about hating police and than proceeding to burn small own businesses down. Granted Granted BLM/Antifa allegory still doesn't exactly make since to me.
I can understand it wasn't exactly well thought out in the movie itself, but some things I noticed about it that add up to that symbolic gesture or allegory:
Tommy in the movie is a literal Antifa leader. Strong when he's in a group, weak in a 1-to-1 confrontation. (The entire mob scene at the end)
The catchphrase "He will not divide us" although not nearly the same i close to the brainwashed chants of "Evil dies tonight."
After the death scene of the mental patient Tommy's basically like "Sorry, but I can't stop now even if there are more innocents." He doesn't say that, but it comes off as such when he says "He can't stop now" or "Has to continue" to Karen.
Michael could be representative of fascist or of evil (opposing views in politics) and anti-progressive speakers. This is why Michael kills a mix raced couple, a gay couple, and then a minority couple almost like a check list of progressive ideology.
They confuse the mental patient with Michael who is obviously nowhere near the same. It could be representing both as being opposed to progressive politicsl Just one is a good intentioned person who says "evil things" so they view him as a great evil. (Again this is symbolic in the film)
Tommy tells the sheriff that he will handle this taking the control from the law itself in one scene. The sheriff or police deuty or whatever says "I'm the law." After the murder no one even arrests any of hte citizens for the complicity in the murder of the mental patient. Just like Antifa/BLM in real life.
Laurie's whole claim about Michael "Being the great divider by fear" seems to represent opposing views/Trump/Facsism.
Michael divides the mob at the end into 1-1 battles where he destroys them, same too with the firefighter scene funny enough.
Basically, like any good propogandist, Jamie Lee Curtis realizes people are turning on BLM/Antifa. So in the movie she's trying to sway them to not be so attack heavy on people who aren't evil fascist (the mental patient) but to violently remove those who are (Michael)... The reason is if they don't stop targetting those who aren't Michael (Fascist/Trump/etc.) then they themselves will be corrupted. The part where the mental patient dies and the guy says "We're all guilty/evil now."
Like I said, be glad you didn't notice it, it's some pretty whacky-do, preachy shit.
The other aspect where Jamie Lee shows herself to be naive of the lefts intention is the whole 1978 scene is referencing police-accidental shootings, which is to try to get Antifa/BLM from attacking the police, and playing up those kind of shootings as accidental and how many cops feel guilt to humanize them to the Antifa/BLM crowd. The thing is Antifa/BLM already won't like this movie just due to things like Michael killing gays, and minorities, and what not.
Just an example from 2018 showing them handpushing politic allegory and symbolism:
In the scene where Michael kills the kid who likes to dance instead of hunt with his dad... It seems to be basically symbolizing toxic masculinity (Michael) kills non-toxic masculine men (the kid who wants to dance instead of hunt with his father.) It was such a weird killing of the kid when outside his family prior to that he wasn't known for killing underage boys or kids.
The reason most people think it's merely a reach is because of how confusing it comes off and not well symbolized or sensical it often comes off as confusing (See Kills example) or aimed at the entirely wrong audience (2018/Kills) You'd practically have to be left wing nut job to see the message It's because even leftist muddle their idiotic messages such as Marvel Comics in recent years and then half way through a message they mess up part of the allegory so that it becomes either tone deaf, or missing the mark. Just like Jamie Lee, or the comments directed about how they're going to make Halloween Ends more political instead of less.