I've thought about that. It's not just since #MeToo started. It has been happening for years. From the time we started creating the annual Top 20 Nude Scenes list until now, the amount of nudity in mainstream American movies has diminished. Every once in a while there will be an outlier like The Shape of Water, but for the most part the nudity scene has steadily migrated from movies to television since 1999. (For the purposes of this discussion, "television" includes original series made for pay services like Amazon Prime and Netflix.)
In 1999, our poll's top 20 consisted entirely of movie scenes.
In 2017, the top 20 are about evenly split between movies and other (television and original content for pay services), and only one of the top three is from a theatrical film.
Why is this true? Many reasons:
(1) More and more of the film industry is controlled by Disney;
(2) The new right movement is built on the pillar of conservative religion;
(3) More and more films are made for general audiences, including kids. It's the blockbuster mentality, which has pushed many personal films and genre films to the side. The Avengers' target audience is everyone of all ages and genders - from couples on dates to families hanging out; sexy films like Body Heat are, by their nature, exclusionary;
(4) The indie film world, once a source of many great films for grown-ups, has basically been consumed by the Hollywood beast. Sundance used to be about writers and directors and ideas and "voices." Now it's about deals;
(5) China is a big part of it. Success in China has become critical to the profit picture for feature films, and China is prudish about nudity, so Hollywood goes full Deep Throat and follows the money;
and probably several more reasons I'm forgetting.
So #MeToo will not be the cause of the decline of sexy movies. That started long ago. But it might be the straw that broke the camel's back.