While the article is thought-provoking and might be useful to a science-fiction author, it's pretty thin on facts and very thick on speculation.
For example, it's true that it is often pointed out that because it also allows for four covalent bonds, silicon might be an alternative to carbon based life. However, the fact that silicon is extremely common here on earth and yet somehow we are carbon based, suggests it simply is not suitable.
Why not? First of all if you use oxidation in order to provide energy to your living organism, oxidized carbon yields carbon dioxide. A gas. Easy to respirate.
If you oxidize silicon, you get silicon dioxide. Sand. It's a little hard imagine a living being which will breathe oxygen in and breathe out sand.
(Yes, there were anoxic lifeforms before we evolved to depend on oxygen, but oxygen provides a highly efficient and effective basis for a metabolic system.)
Furthermore, the covalent bonds formed by silicon are more fragile than those of carbon. That is enough in itself to make life based upon silicon difficult to maintain, but it also means that lengthier and more complex molecules are formed with carbon which could not be formed ot maintained by the substitution of silicon.
As for the other autocatalytic chemical systems that were studied, that's way beyond my level of knowledge, but I have some hesitations there too.
If life is so incredibly common in the universe, why is it that of the three planets which are terrestrial in nature and found in our solar system's Goldilocks zone, only earth is clearly teaming with life? One out of three makes it sound like life is actually rather rare and unlikely.
Still, it does make for fun speculation. Hal Clement was noted for his interesting alien life forms in his science fiction novels. I think I need to go back and reread some of those; it's been a few decades.
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