Frankly, antitrust laws should prevent loss leaders from being a thing in the first place. Whether it’s to get people in stores because of an amazing deal, people to buy into your ecosystem because hardware isn’t that cheap otherwise, or using venture capital to drive competition out of business by offering prices subsidized by investor money that others can’t compete with to drive them out of business and set whatever prices you want, it’s all anti-competition (especially the last one, that’s blatantly trying to set up a monopoly).