I don't think this lawsuit has much merit, but the lawsuit is arguing against damages to an overall portfolio. If a diversified portfolio consisting of Coca Cola and Pepsi was on the whole damaged due to the actions of Coca Cola against Pepsi, then the plaintiffs argue that Coca Cola would be liable for some part of that damage.
If, however, Coca Cola's actions harmed Pepsi specifically but benefited the overall portfolio, then no damages would be pursued.
So Coca Cola is welcome to take market share from Pepsi so long as doing so is a net benefit to a diversified portfolio, as opposed to doing so in a way that harms a diversified portfolio.