The question isn't whether it was OK to turn the gun emoji into a water pistol in the first place.
It doesn't matter if it wasn't. It was done, and it was done at a time when there was political will for everyone to follow suit and be consistent.
The question is whether it's OK to turn it back. Because there ISN'T the same political will. And other emoji providers will NOT follow X in this.
Having X "go back" because the original change was "unjust" doesn't fix the underlying problem. It creates a new one.
Literally perfect application of the concept of "two wrongs don't make a right"