Yes, there is - and historically has been - a lot of 'shock' bait on Tumblr. Unfortunately there have also been many marginalised sex/gender groups that have built/found communities there that are likely to be affected as well.
I've always been amused? in the sexual prudery of so many quite accepting of violence pr0n. A rigid dichotomy that is amazingly brittle and self righteous.
Frankly, if those communities do get the boot rather than being accommodated as adult rather than pr0n I expect that Tumblr will be terminal.
Over the years I made several attempts to incorporate Tumblr into my SMM mix but nothing gelled as I'd hoped. Still, I never like to see a channel disappear.
For the people whose website habits are not as deplorable as mine, here [cracked.com] is a sampling of what Tumblr deems to be adult content (along with a specimen or two of content they have no trouble with).