I also had my blacklist fail to block what I wanted, which is feces in general, due to the term "scat" in it being changed to "scatplay" due to this bulk tag update. Didn't notice that it wasn't blocking posts with feces depictions until today when I got blindsided by a "hyper_feces" tagged image.
Thought at first the post was mis-tagged since it didn't have the tag "scat," but the comment on the post from someone complaining their blacklist didn't block the post hinted to me to check my blacklist, which quickly revealed the tag name change to one less encompassing than it used to be.
Now, I'm not saying revert the bulk tag update, but a change of a tag in users' blacklists to one that covers less, without informing those users, is gonna lead to a few nasty surprises like I had.