There's been a few. Remember The Crying Game? There was also a massive hit in Australia called Priscilla which though technically just about drag queens was a big normalizer for that type of stuff here.

As Archvile said as well I think they kind of just snuck the whole trans thing in like a pork belly on the whole homosexual agenda. Given how closely those two issues are related in the common mind I think people just accepted the trans stuff as just a more exotic expression of homosexuality.

Something also to remember is that they need these tactics less and less now because they are so ubiquitous for Western people in the media they consume and the things they're taught in educational institutions that for many you'd have to use the same tactics to get people NOT to accept these things.