It'd be a bigger strategic blunder for China to cut Pakistan loose.
Basically, the Chinese know (or now know) the caliber of our rulers. This shouldn't have been news to them, but anyways, it's as clear as glass that our political and military leadership aren't "it." As a group, they're not even able to defend Pakistan's national interests, forget helping others (except for the U.S., which seems to have a stronger grasp of the situation).
However, China can't change geography or strategic realities. The U.S. is on China's case. It'll use India even more so in the coming years to get on China's nerves. Pakistan is the perfect release valve for any pressure India puts on China.
The moment Pakistan's leadership develops "it" (i.e., genuine independence and aggressive foreign policy re: Kashmir and Afghanistan), China will extend its hand to Pakistan. That's the ally they want. However, if they cut Pakistan loose and, worse, the U.S. really steps in to create yet another anti-China ally (even a tier-2 type to India's tier-1), then yeah, China's fully encircled.
Simply put, China aren't leaving us, but they aren't taking us seriously either. Like our ties with the U.S., we're entering a weird hazy zone with the Chinese too due to the indecisiveness, corruption, and listlessness of our leadership.
As china has no history of conquest and invasion in the recent past---it really has no idea how to own their allies.
The americans the british will fight tooth and nail to keep their allies---even pakistan.