Each zone in the game has a range of levels for its npcs.
The zone also caps the Effective Level of players when inside that zone.
This is based on the zone's base level.
The level cap for a zone, that limits players when inside it is Zone Base Level + 5. *
So for the Orcazelos Desert, initial zone of the game, we have Base Level zero, and effective player level cap of 5.
The new Solace of Q'ro, under the desert zones are to be base level 5.
Player max level will be increasing to 10.
Mythical creatures are generally, like quest giver npcs, to be Zone Base Level + 10 (5 above effective player level cap in that zone).
The idea is that going forward, some zones base level can be increased in line with the current player level cap, to keep them relevant, i.e. raid zones.
*
Five is the magic number in QMR's levelling system, equating to a doubling of power in all stages of the game.