Your claim doesn’t really match your reference, also, I don’t really care (and neither likely does BLM) care about what people like you think. React less to clickbait headlines, think more critically pleaze.
I saw BLM Chicago instagram post myself, the referenced link is simply for proof.
They celebrated an attack on Israel that resulted in deaths and kidnapping of hundreds of innocent music festival goers and kibbutznicks the day after that vicious attack.
The fact that you don’t care what I ( or people like me - whatever that means) think is irrelevant to the discussion