A hard fork that would increase the coin supply.
There's no reason to ever increase the coin supply. Not-even-one. The system works currently with
this circulating supply and any change in it would be consensus-ly irrational.
The only reason will be when Bitcoin has been completely mined and has been lost through the centuries. We do not have to worry about that but in 5 centuries when people have lost Bitcoin because of death Bitcoin could become instinct. That is the only reason why Bitcoin should be increased but that is assuming if Bitcoin is still here in centuries.