Duterte is rejecting the most powerful ally in the world. His actions create a lot of instability and concern among its people. With instability, comes anger and with anger, comes a call for change. As Duterte is acting more like a dictator rather than a president, he will be overthrown if and when his policies cause harm to the safety of the Philippines.
Duterte is treading a very dangerous path. The Philippines is anything but a world power and it needs all of its allies and potential friends in order to thrive. At first glance, the people of the Philippines might admire the strong show of leadership but when the economy suffers and the people no longer feel safe, yes, he could face the threat of being overthrown.
If he continues to degrade his countries relationship with other countries, the Phillipines will have no protection from outside forces and will become vulnerable. They will also soon find themselves without any trading partners. These two things could cause the citizens of the Phillipeans to revolt against him because he is bad.
There are many other factors which must be present for the overthrow of a national government. First, the neighboring countries must be unwilling to support Rodrigo Duterte's decision to remove all foreign troops. Secondly, the international community must express its dissatisfaction with a trade embargo that could inflict economic hardship on the Philippine people. Regional conflict and economic sanctions are more likely to lead to a government being overthrown, rather than the perceived isolation when foreign troops leave their soil.