The group has a copyright logo in the name of the group, which ROBLOX can get sued for, so, in order to keep this site running and not get sued by a company 10 times richer than this, this group needs to be banned right away.
ROBLOX cannot be sued.
They would simply get a notification from the copyright owner with a copyright claim; ROBLOX would then remove the assets with the copyrighted material.
Until the copyright claim is made, I don't see any reason to ban the group.