I mean, according to what reference we have in WC3, apparently the Bunny race from Bunny Island are hostile to adventurers (with exception to Funny Bunny).
Why does it have to be cutesy? The race doesn't exist in WoW yet, it could take any direction they wanted. It seems the Bunny race of WC3 shared some visual similarities to Furbolg which could imply some relationship or ancestry to them. They could always take them in a completely new direction and make them more bad-ass if they wanted to.