It's not as simple as outlawing gerrymandering. You literally have to be able to redraw district lines under the current electoral system because the districts need to have roughly the same amount of people. If you never redraw the lines, the natural population shifting will lead to districts that have either way more or way less power than other districts, which goes directly against their purpose.
If you switched the electoral system to one that doesn't require districts, then you could outlaw gerrymandering, but I don't think that's what this campaign is about.