it is a 50% minimum divergence to break the security of nakamoto consensus, the "heaviest chain wins" rule

even if a fork with bigger rewards gets ahead by one block chances are that two blocks will be mined that are from the canonical reward maximum and one of those is smaller hash

unless someone also somehow gets 50% of hashpower to not just allow bigger rewards but REQUIRE them haha yeah, nah, not gonna happen

because of the culture of bitcoin, the chances of enough miners AND node runners updating to a new schedule are basically not much better than the chances of cracking a bitcoin key