That's correct, you can read about the process here. The AEC takes submissions from the public into account when making these changes, and it's worth noting that The Greens did appear to support some of the changes that were made (moving parts of Brunswick and Fitzroy from Melbourne to Wills) although their suggestion to move Kensington and Flemington into Melbourne wasn't acted on. Perhaps The Greens saw the boundary changes as potential to gain another seat, which is why they supported shifting some of their voters out of Melbourne and into Wills. I don't think anyone went into this election thinking Bandt was under threat, the general vibe was that The Greens would continue to make gains based on the decline of the major parties.