The term doesn’t imply any sexual relationship. It means they are close colleagues and got each others backs at work, and can safely talk shit about the workplace with each other. I don’t think it’s gross but probably there could be a better term, maybe workplace besties?

Edit: I will add, that if it’s a manager/team member or some other connection that is leading to favouritism or unfairness in the team that needs to be addressed. But other than that I really wouldn’t care what people like to call their friendships.