That is a very good question, from public information I can gather around Ant and Ma's career in general, it seems he has strong backings from a wide range of powerful people due to financial relations as well as his reputation -- he is the Elon Musk of China and commands tremendous respect and pride among not just citizens but also top leadership.
In fact, his backing is so strong that China's banking and financial regulators have not been successful at regulating Ant despite other fintech pioneers' blatant failings. However, this time he miscalculated how far he can push and the more conservative voices in the party have finally gained an upper hand.