Just looked up the cancelled vs canceled and either one is valid. English use two ls more commonly and Americans use one l more commonly. I’m American, but used the two l spelling. (Edit: sorry, you were asking about hashtag vs non-hashtag).

As far as the post title, Musk didn’t cancel anyone officially or otherwise. Saying so implies he kicked them off as a valid advertiser from his platform. He did not. (Edit: maybe he canceled his own subscription for his little kids? I didn’t catch that in the video, just thousands of X users having done so).