The rising dislike of the tech giants and the anti-trust investigations are extremely similar to what is happening in Europe and the US, so I don't particularly see why this is some sort of surprising thing requiring special explanation.
It's the proximity of the situation to Jack Ma's comments that tips you off as to the true reason for the actions. It's not just normal anti-trust, the timing suggests an attempt to punish any opposition to the CCP or Xi.
At some point one is gonna get timing right or the act right. It seems to me chinese government has got their act right.