I took Khan's tweet about Amess to be respectful and considerate. His family may be comforted to hear of the respect in which he was held and the sorrow at his death, but they don't necessarily want to be reminded of the manner, or the brutality, of his killing in every post - I wouldn't if I was related to him.
The same doesn't apply to his Floyd message, which is directed to Khan's own constituency, not to Americans or to Floyd's own family.