One plausible theory is Apple was engaging in an act of game theory. By drawing attention to the 90-day free trial, Apple could have diverted rights holders’ attention from other deal points (such as advances or minimum revenue guarantees). When Apple agreed to pay during the free trials, rights holders would feel they had gained a concession. In reality, Apple never expected to win that deal point.
Source: Taylor Swift’s ‘Win’ Over Apple Shows How Smart the Tech Giant Really Is | Billboard