Try contacting the Tumblr staff and be patient, I read elsewhere that this is likely a mistake as they're trying to flush out rampant porn bots that keep giving out links to suspicious websites, which prompted Apple to drop the Tumblr app from their store.

They appear to be doing this to a lot of Adult rated Tumblrs without any reason given yet.

If you contact them, they should restore it. I think they are working on it but i think you can push it for faster results.

Supposedly, it's a glitch in the system but it also might not be.

Apparently it's a rushed Bot system that is straight up banning/erasing blogs due to NSFW content.

Tumblr got removed from the apps stores of many OS' because of "too much inappropriate content", which is bullshit but okay. But yeah, email them, it'll be pain in the ass, but it's absolutely stupid.

Apparently one of the majour things that triggers this for some is external linking, meaning linking to other places on the posts themselves (including patreon and twitter because fuck content creators right?)

From what I've heard, it's a bot they created to delete porn bots, and it's accidentally deleting actual accounts.

I know its a little late, but many people from tumblr migrated to baraag.net
Kind of a twitter clone, no rules or anything