Did they interview these top scorers what they intend to study in universities? The SCMP article mentioned some but not all. If past record is any guide, most of these straight A students will end up going to either medical school at HKU or CUHK or law school at HKU or CUHK. That might be some statistical science (data scientists are increasingly in demand), business admin major at other UST or an occasional social science major. But most will end up as doctor or lawyers.
I'm not an expert on what the IB covers, but it would certainly seem a shame if the top academic students end up going into largely vocational education at tertiary level.