from your link, "Apple doesn’t detail its current ad revenue, and analyst Samik Chatterjee seems to imply that the number could only be reached by including some form of advertising within or around Apple TV+" and "Apple’s most recent earnings report revealed that it earned $12.51B from Services in calendar Q3/fiscal Q4, though there is no breakdown on how much of this comes from ad revenue."

so it seems that the current revenue is a guess and the projection is a guess.