You are assuming about what you think I'm assuming.
Time consuming mechanics prior to endgame is pointless in this generation as it will not go by well. You fail to understand that if a mob pops every 21 hours do you think, in a populated MMO, you will be the only one there? It will become time consuming for an item you MIGHT get and WILL out level.
Such "waiting game" time mechanics before endgame will be a wasted effort and looked at as a negative in this generation.
Why is it waiting game? You will set up camp before the pop, probably with a bunch of others, and still hope the others or someone passing through doesn't lay claim to it. meaning you will have to wait another 21 hours to get a shot at a low drop rate item.