I can't open the article.
In theory, it's a sound idea. The skills needed for Biology are completely different to those needed for Physics - Biology is far more language-based, while Physics is far more Maths-based.
Having said that, in practice, good luck with recuritment. I can teach all 3 sciences, but I work in a school where, strangely, we have a glut of Physics teachers - yet there is no specialist Chemist. So despite my degree being in Physics, I now teach Chemistry.
Incidentally, Chemistry will suffer as a result, too - not just because of the lack of specialists, but also because children either gravitate towards Physics or Biology, but less so towards Chemistry, which has always been middling between the two subjects.
On a practical level, it will be a nightmare for timetablers (who now have to fit 2 extra subjects into the timetable), and a nightmare from a curriculum perspecitive - for example, out school currently teaches 5 lessons of Science a week - that cannot be divided up between 3 subjects, so will need to become either 6 lessons (therefore pushing a different subject out) or will go down to 3, for which there is too much content to cover.
On another practical level, it will mean the end to vocational sciences, which aim to combine all 3 in a topic-based approach, so a new curriculum will have to be developed. It will also neccessitate a rewrite of KS3 Sciences.
Oh, and separate budgets, technicians and specialist lab spaces will be required.
More workload, fewer specialist staff, a likely decline in Chemistry education and unlikely to result in better outcomes.