I mean, I can agree that simple autocatalytic reactions can occur with chemistry based on other elements… but it’s a stretch to say that suggests “alien life might not be carbon-based”. Maybe very, very simple, life-like chemical systems, but life as we know it is defined by large, many-atom molecules, and no other element can do this the the way carbon can (not even silicon, whose bond energy decreases with catentation of more silicon atoms link, which, combined with it’s poor ability to form multiple bonds ruins the possibility of silicon-based life). Anything that we can conceivably think of as “life” beyond simple self-reproducing chemical, or bizzare Boltzmann brain-esque systems will have carbon-based chemicals in it.