This is Apple's second sponsored research report in as many months (the first was designed to support the value-add of the App Store walled garden model). It's definitely starting to feel like an orchestrated strategy by their PR department.
Unfortunately, I found this report less convincing and objective than the first one. In particular, the distinction between first-party and third-party data (which the author takes pains to clarify that Apple does not use) is both technically correct and immensely self-serving. The argument all along has never been that Apple violates the terms of ATT...it's that Apple gerrymandered the entire precept of ATT to ensure its own behavior was not a 'violation'.
Said another way, Apple is the most valuable corporation in the world and has multiple internal business lines (which conveniently qualify as 'first-party' to both each other and the OS itself) that directly compete with entire third-party industries outside the company. Basing ATT on an arbitrary first-party/third-party definition has always been the underlying issue.
However, there is one reassuring thread in this report: for anyone who still held lingering doubts as to whether ATT might be intended to apply to measurement of owned and earned channels, or UX functionality like deep linking, this report should put those doubts firmly to rest: these first-party uses of data were clearly never considered in scope.