Just a thought from the practice:
ITIL certifications are a business model, and for this reason alone there must be something "new" every few years.
I don't see any real, necessary changes worth mentioning, quite the contrary!
In v2/3 we wanted to protect the 3rd level from unnecessary standard requests for cost reasons. Therefore the SD and the staggering over 2nd level.
In v4 you should chat across the board, also with the 3rd level support (swarming), which has exactly the opposite effect, your support will be more expensive!
This is just an example where the ideas contradict each other.
As I said, ITIL is a money machine and basically nothing more than common sense.