However, it is not impossible that a fork is decided and changes that rule.
Who decide?
The common use is that the chain with more hashing power behind would be called the "true Bitcoin" and receive full support from exchanges and users.
hashing power mean nothing, branding mean nothing, I hope I'm a bitcoin user, I will never support a coin I don't like, no matter how much hashing power it have.
Are you aware of how forks work? Have you heard about Bitcoin Cash and Bitcoin Gold? A majority of miners could decide that there will be 41 million and change the issuance rate and...
It doesn´t matter what you support, because if you are in a network that has not the maximum hashing power for the algorithm your network is not secure.