This is sort of "terrain" exploit similar to "jumping" in Ironforge Wall that everyone can jump to invisible Wall.
It should never be allowed since it must be done by "tricky" way (i recommend any nostalrius staff to test) .
If there is any caster up there - there is no way the melee would be able to jump there (such as Paladin) .
Only Warriors and Mages can abuse this easiest "invisible Wall" due to charges and blinks , while others should take long time until they get up there and is wasting of Battleground time if Flag Carrier sitting there.
Not everyone know how to jump in this spot , neither many are familiar with that.
Only the pro PVP abusers or Hardcore PVP players know this.
This is the only way to jump there which i honestly see that as Abusing Spot :
https://www.youtube.com/watch?v=22XMywy_tbsSee at 0:44 (the horde player) .
This should be Banned.