There is still a lot of Adult Content on Tumblr, and across all Genders. And yes there is a lot less, but not as open. I heard the real reason behind the restriction of Adult Content revolved around changes brought about which allowed. The pursuit of the First Party in Legal Action against Second and Third Parties Online for and over Solicitation. Another attempt at stopping Prostitution and Sex Trafficking. Several new Laws were signed and implemented beginning in April of 2018.

And one can still find Adult Content of good to high quality images and story lines as long as it dose not promote the Sexual Act and those that do are being slowly removed. We may see further changes in much the way Facebook has pushed their Community Standards.