Who cares about that it comes back.
If you happen to have an ilvl510 upgraded Starshatter it's better as the ilvl509 Shin'ka by a lot, and since there will be no-way to upgrade Shin'ka to ilvl 517, there is no point for me to even go to Terrace, to even get it, the legendary gem weapon is all-of-a-sudden usless, which was supposed to be the best weapon raid progress wise.
It just makes not sense, to remove item upgrades for 5.0, 5.1. There's even a bigger gap for normal gear. The upgrade on some items is simply amazing.
I really don't care if they remove the item upgrading forever from 5.2, but they should leave it up for 5.0, 5.1 items, it's that simple. People are in the middle of upgrading, and why would they fuck them over now, for no reason at all, the "damage" has been done, just leave it in, don't allow 5.2 items to be upgraded, everything is fine.