Baumol

I am puzzled why you are asking this, because if you look at the syllabus on the ACCA website Baumol is specifically mentioned. (Also we would not have it in our free Lecture Notes or our free lectures if it was not in the syllabus).
It is still in the syllabus.

However, it is extremely unlikely these days that you would be asked for calculations on Baumol (even though in theory he could do). If it is mentioned in the exam it will almost certainly be part of a written part of a question.