Not only did the attackers post a fake mint link, they took steps to prevent the project from thwarting their attack by banning other members and removing user rights that would have allowed other project members to delete the fake links. They also added a bot to the server that locked channels so people couldn't send warnings that the links were fake.
The Rare Bears team did eventually regain access and secured their Discord server. In an apology posted on their Twitter page, they addressed the multiple security breaches that Rare Bears have faced to date, and said they had "stepped up" and would be having a firm audit their project.