You can't be sued for abusing monopoly power without first having a monopoly in the relevant market, keeping in mind that 'monopoly' and 'relevant market' have

You can't be sued for abusing monopoly power without first having a monopoly in the relevant market, keeping in mind that 'monopoly' and 'relevant market' have specific legal definitions. At the time of those sanctions, Microsoft was deemed to have a monopoly in the "Intel-compatible PC operating system market". AFAIK, there is no market in which Apple is considered to have monopoly power.