If this is about something like being able to get T4 loot without being high enough level to access the difficulty I agree you should get Tier 4 rewards, although it would be better to just not let you use them items until you reach a certain power requirement rather than just outright not granting you T4 loot. Would be the same as other games where you go to a high level zone and get some loot you can still get that high level loot to drop but you cannot use it until you reach a certain level requirement.