Remember that it's not muslims, but Islamists. The Peshmerga are the bravest fighters in the Middle East, and are protecting Christians and Yezidis, and they're mostly made up of muslims. So it's best not to generalize.
When it comes to geopolitics allies are often enemies. Saudi Arabia, Qatar and the other nations are the biggest financiers of Islamist insurgencies. The interests of the ruling party of Saudi Arabia, the Saud family are not the interests of the clergy in Saudi Arabia.
The U.S. will never become allies with Iran and Assad. They will continue arming the Kurds. If the U.S. really wanted to they could basically make the Peshmerga into a heavily armed world class army, and destabilize Iran. That might be a strong possibility of what will happen.