The Arab-islamic world is made up of autocracies; they don't need to care about a lot, and they indeed showed extremely little concern for the Palestinians as well.
Regarding organ harvesting, the FBI arrested Israeli-connected illegal organ harvesters in the US, as reported by the New York Times. The Palestinians have complained about Israeli organ harvesting, and apparently the US is concerned about their illegal organ harvesting networks too.
For the second, I don't know anything about it
For the Uighurs, there are allegations of 25.000 murders a year for organ harvesting in the Xinjiang.