If “All Lives Matter” is used outside of the context of BLM, then it is harmless. If it is used inside the context of BLM it is a racist dog whistle. That said

If “All Lives Matter” is used outside of the context of BLM, then it is harmless. If it is used inside the context of BLM it is a racist dog whistle. That said, I stand by what I said that most of the time it is being used in the latter case. Wikipedia has an article about the latter case, not the former. Searching the term in any search engine will have you scroll very far down before you see it outside the context of BLM.