The short answer is obvious: take the government out of the OP and there is no OP. Take the government out of the responses and there are no responses.
The longer answer follows.
The government did the right thing because after years of pushing for it they are in some cases but notably not all being forced to recognize the constitutional requirement to do so. There are therefore two points being addressed (note that my comments are directed specifically to TST and not others since TST has an explicit purpose that includes this activism):
First: ensure that government compliance becomes the norm and not the exception by continuing to exercise it.
This was done, and without resistance, and we all applaud it.
Second: assist with the first by making it plain to the majority religion that non-majority-religion participation in such displays are legal, moral, and inevitable.
Also done, and done here with no resistance of any kind, even for a pretend religion. Three cheers for the State, doing the right thing, right away.
As I see it, exit stage left for the State WRT the OP. Great performance, well done. So, as I sharpen up my pitchfork in anticipation of protesting the govt stepping on rights...what are they doing wrong, again?
Allow me a crude analogy: It is legal but inappropriate for anyone to fart in an elevator, but if the police are called to eject only atheists who fart there while celebrating the Christians who continue to do it, and moreover the larger Christian community continues to applaud elevator-farting Christians while denouncing elevator-farting atheists, then it is not I who am being dickish when I go into a crowded elevator specifically with the intent to fart there.
Please be careful: there is a poster popping in and out that will flat out crucify your ass for such an alternative universe fan fic hypothetical. I expect his howling presently.
Ok: so using your analogy, and of course not over-analyzing it, who in this Op tale is having the police called on them? When the christians and seculars (we keep forgetting about the nonreligious celebrants, don't we?) fart, they are farting to fill the air during a major celebration. All are welcome to fart along, as I see it. Or not fart, if they choose. Or fart differently. Whatever.
Who has called police on the Satanic farters? Saying it happened before is not entirely relevant. That's more of a farting-reenactment. Or maybe like a World Fart II soldier staggering out of the woods thinking the fight is still on.
Who called the metaphorical farting police on the Satanic Temple?