I think you have to have a lot, and they have to be mostly your original posts? At least, a lot of people I follow have a few flagged posts, but only one person was ever shadowbanned.

Eh, I’m not too fussed because I saved my whole Tumblr right after the original announcement. Everything before December 2018 is backed up, and the stuff I’m posting now I either don’t much care about archiving or if it’s special (i.e. art I want to keep) I make sure to save a copy of it elsewhere. It’s like the 1990s all over again in here!