Miners can't enforce changes that the economic majority doesn't agree with or they will find themselves mining worthless coins.
So, miners can attempt whatever they wish, but they had better hope they have the interests of holders in mind.
That's the question. If miners aren't large holders then one can hope they have interests of holders in mind but that would just be wishful thinking. All market participants have only their own interests in mind. I understand they can't change the rules. This is simply a speculation on what are the different issues that may come up.
That's exactly why decentralized mining is the key to the safety. Once centralized, the miner can do whatever they want to the blocks they generated, but as long as the mining is still decentralized to certain extent, they can only follow the rule.