Ion is 100% right when he says the early access with give players no long term power and no long term leveling advantage.But where he is wrong is the gatherers who will take herb mining and have 3 days to strip mine and herb and prepare stocks of new regents for the AH. That's going to be a massive advantage to them short to medium term. Long term it doesn't matter.
What I find extremely funny and for some reason everyone seemed to forget is that Dragonflight's Epic Edition was also $90 and DIDN'T have guaranteed beta and 3-day early access. So the way I see it, there is no extra charge for early access in War Within.