Deviations in agreements is not a thing exclusive to China. Agreements in international politics are made for a purpose. Perhaps to keep peace, or to protect some interest, etc. If the situation changes such that that purpose can no longer be served — especially if that purpose is an extremely important core interest — then any country will seek to deviate from agreed upon behavior.
For example, the US clearly agreed on the One China Policy but they are now changing it. Because the US no longer values the original purpose that the One China Policy served.
So the question "will China renegade on its agreement or not?" is best answered with another question: "What is China's core interest? What purpose does an agreement serve to China?"
It is unfortunately here where big misreadings happen. Popular western understand of China says that China does things because they are "authoritarian", "expansionist", "power hungry", etc. But a true analysis of China's interest would show that one of China's core interests is territorial integrity, defined largely by the territory it had inherited from the Qing empire in 1911, and the Republic of China in 1949. China's policy on territorial integrity has not changed since 1949.
We may not always agree with China's interests. Maybe they conflict with ours. But properly understanding those interests will at the end of the day surely yield better outcomes than misreading China with stereotypes.