In the current issue of "Entertainment Weekly", featuring Star Wars on the front, there is a two page spread (pg. 28-29) about Janet Jackson's career according to Janet herself....the only reference to Michael is the 1995 "Scream" video, about which she writes (and I quote): "She says the best part of shooting the edgy video with Michael Jackson was "doing something that was different. And I know my brother loves to do different stuff. I should say 'my brother loved'. It's as if he's still...well, he still is around. And it turned out beautifully."
Thank you for mentioning this, it doesn't really feel like a slipup to me either.
It's like she said so in purpose.