They are still useful. 50% of the syllabus is still the same. For example, the module 5 Le Chatelier's Principle was in the old syllabus. Other topics such as naming organic compounds, polymers, molar heat of combustion, atomic absorption spectroscopy, titration, molar heat of combustion, K constant calculations, all the acid-base theories (lavoisier, arrhenius etc.) are also there.
The main differences between this new syllabus and the old syllabus is they deleted the option topics section (i.e. you would do 3 same modules as everyone else in the state, and then your school would select an optional topic like industrial chemistry that you would do in the exam out of the 4 or 5 option topics). So essentially they consolidated the main areas, deleted some not so important things and added a few new topics like NMR, mass spectroscopy, IR sections.
You just have to be able to tell what topics are relevant and not. However, the questions are still very useful if you are trying to do more practice on a specific area. If you are just trying to do full papers and simulate the time conditions aspect then that is a different thing where doing the modern papers is better idea