not at all.
A lot of the game is lateral progression via equipment.
A brand new player with some equipment and friends can certainly take on harder mobs right out the gate.
This is shown by your good example.
in my suggestion you would just have to give them appropriate clothing to go and play in the harsher climates.
Just like going to aerhen now. you dont go to the really cold or hot places without appropriate basic gear or skills.
these basic gears (cotton cloth vs rabbit cloth for example) are easy to get and not a real obstacle.
The goal is to give higher 'rank' players more content while not simultaniously making it too hard for other players or creating a situation where the higher 'rank' players steamroll the lower rank players along with whatever mobs they happen to be farming.
If a group of lower rank players decide to gear up and go to the harder place, they are still going to do well and -if- they run into a solo higher tier player they are less likely to get eliminated as they went in expecting it to be more challenging and so brought the numbers to counter it.
I hope that any farm bots or killing-for-cash solo players are also more likely to be identified and dealt with with this system as they would stick out even more then they might otherwise.