As Sakero has said, this was brought up on Tarnished Coast at the Multi-Guild meeting which a Developer did attend. There is no pvp, pve, monetary or skill benefit, or item advantage or exploit in using the un-instanced area of Salma so why take the time and effort to prevent the area from being used when there are far more pressing concerns to deal with.
There are a number of jumping puzzles in the game, so I am at a loss to understand how such a simple one could have been overlooked. There is a second spot to access Salma in the same manner that has been blocked, so my contention is this specific method of accessing Salma is an easter egg that we were meant to find.