Tumblr is a blogging platform that has been part of Yahoo (or Oath, as it is now) since 2013. However, the parent company in this case - Verizon - has reportedly been trying to palm it off for some time. It has now successfully found a buyer: Automattic Inc, the same company behind WordPress.
https://www.notebookcheck.net/Tumblr-is-to-be-sold-to-the-makers-of-WordPress.430325.0.html
Looks like money laundering or sabotage - don't tell me a CEO of an active web company had no idea that banning NSFW would destroy the platform otherwise.