Srsly just put a priest and 2 mages to the "backdoor exploit" and everything is fine. The majority needs like 2 minutes to manage the jumping up there so just kill em and walk back if you need to, it's not that hard.
How shall they change it? Ban everyone that jumps up there? Place invisible walls or even edit terrain?
It's just incredible difficult to rework this properly (just look at DM """"fixes""""). Besides that it is totally blizzlike even if it's unfair (the whole AV is unfair, yes even whole Vanilla was unfair)
I'd advise you to move on and adapt to these "new tactics" - I've had several AV's yesterday where Alliance succesfully defended with 5 man vs like 15 just because they could move back safely without horde warriors rogues etc coming close to them. Horde will need a shitton of casters at the "jumpspot" to prevent alliance and even then alliance mages could just blizzard the spot to make it impossible to jump over there and when they die they rez and repeat (while their team is winning in south).
Instead of waiting afk anywhere in south of AV and complaining about this being unfair just get your shit together and adapt!
TL;DR: Most likely staff is not going to change anything about that "exploit" because it is blizzlike and difficult to "fix". Get over it
Greetings from Horde side of the bridge as I prefer the common way