I do not remember there being a major change, but I do not keep copies of old syllabuses.
If you are watching my free lectures, then they are up-to-date for the current syllabus and you do not really need a Study Text.
The essential book (however you choose to study) is the Revision Kit because it is full of past exam question to practice (and practice is vital for passing the exam). It is always best to have the current edition of the Revision Kit.