Why is everyone complaining that they're taking away Aatrox's revive?
Just build Guardian Angel. 
Just build Guardian Angel. 
People are complaining because the built-in revive was the only vestige of Aatrox's old kit. It was a part of his identity.
Personally, I think they could try a little harder at balancing it. Reduce the health he gets back on revive, but if the duration ends and the revive is available, let him empty the blood well and heal over time. This would let him get a bit of value out of it even if the enemy disengages and doesn't let him get the revive off, while making the actual revive weaker. Or make it kind of like a Sion passive, where after he "dies" he gets a limited window to fight and earn the revive.
Ohhh having Zil support + GA + ult sounds like a lot of fun tbh 😂 as much as I dislike aatrox removing his revive would suck especially for the old school aatrox players, they gotta find a balance but I guess if riot were to balance him around his ult then he would end up gutted to oblivion like old aatrox.