i kind of feel the opposite. there are soooo many halloween specials. pretty much every kids show has one. the difference is these days there are dozens of places to watch TV so none of them are "special" or have any cultural impact. it's the opposite of the days when literally everyone had to watch live TV,.. there was only 1 new halloween show a year and it got promoted to high heaven and everyone watched it.
off the top of my head:
Disney+
Last year they had the haunted mansion Muppets special and there was a lego star wars thing.
this year they had hocus pocus 2 and there is at least 1 other movie i saw getting promoted
NetFlix
i mean, each year they have at least 3-5 horror films/series launch in october. i think the main event last year was nightbooks and the fear street trilogy. i also remember sharkdog launching last year. i cant remember when they released but captain underpants was good, spookly was good according to my kids, hubie halloween was good, they love super monsters halloween, and carson, and frankly a bunch of others i can't remember.
i just got back from Malaysia so i'm a bit out of the loop this year but so far i've watch the latest season of nailed it halloween and phantom pups. i'm sure there are more.
i'm done now. i don't watch the other services and i don't care to look it up.
in summary: there are more halloween specials then ever and because there are soo many none have a lasting cultural impact and thus they are quickly forgotten.