It will happen in several decades. Countries rise and fall. When it rises, it expands; when it falls, it contracts. USA, China, Soviet Unions, Britain empire, Roman expires, Islam Empires all behave like this.Well I don't know that anyway sure they can send their military to go Mindanao if they can
Unfortunately for Philippines, it chooses the wrong side at the wrong time at the wrong place. China is rising and expanding. It will get back its own regions; United States is over-extended, falling and trying to find its defense lines for contraction. Philippines with belief in Catholic is also alien in Asia and have no true friends in Asia. Even Vietnam and Japan can only align with Philippines for geopolitical reasons. Philippines is very weak but wants to be the forward in conflicts of civilizations. It will be tore apart like those countries in mid-east or Eastern Europe.
For vietnam and Japan, no matter China or USA is the winner, they do not suffer a lot, they just switch sides. But for Philippines, if China wins, Philippines as the last colony of Western civilization will be gone forever.
The current station of US army in Philippines in the last efforts for the West to keep the last colony of Western Civilization in Asia. If one day US army has to withdraw due to geopolitical failure or economic burden, I bet that Philippines will be shattered in many island countries.