Police were called on someone acting suspicious, they found someone matching the description, so they stopped and tried to talk to him.This is literally "walking while black" because it's NOT illegal to wear a ski mask OR wave your arms in the air to music OR to be outside doing those things. Also in my opinion it is not particularly suspicious because; does someone with ill intent walk around with a ski mask on and draw attention to themselves, or do they keep the ski mask hidden away and try to draw as little attention as possible until just before they are ready to commit their nefarious deeds?
Let's not forget that a black man had the police called on him by a Karen for walking in the park in broad daylight and it made national news and became a meme. Another black man out for a jog was killed by two vigilantes and the DA is now under arrest and investigation for covering it up. Context matters.
The police didn’t invent this call, they were called to investigate a complaint and attempted to do so.