Aircraft certified for high elevation operations normally have an override of some kind or a procedure (old aircraft) to deal with the high cabin altitudes. Typically on a modern aircraft the cabin alt warnings are re-set to higher altitudes based on landing field elevation and the pax oxygen dropout shouldn't be effected as it's usually above 14500' cabin alt. The cabin pressure is still scheduled to LFE -2 to 300' on touchdown then a gradual depressurisation during the landing rollout.