I no longer have the 2015 syllabus and so I cant remember. I think very little has changed.
However the format of the exam has changed a lot, and so you really should buy a current edition of a Revision Kit so that you get used to the style of the questions.
If you are watching my free lectures then you do not really need a Study Text – the lectures are a complete free course for Paper F9 and cover everything needed to be able to pass the exam well (and are all up-to-date for the current syllabus).