AFAIK the so called Tumblr migration is because of their NSFW content. Like yes, there are art stuff involved, at the same time though, I have seen porn/nsfw there for innocent search terms like "italian" or some other country.
The NSFW crap I've seen has also been spam bots / porny spam bots also.
AFAIK, instead of putting in human resources to moderate content (ie who is paying the moderators and where are they from?) they just went with an outright ban and set rules on what to ban and I don't judge them harshly on it.
(and for some toot that I came across to DoS / annoy Tumblr Support, being an ass to Support people is not going to help and lol at trying to 'DoS' Tumblr)