I've read that the author may have some opinions regarding AI that may be considered religious, but this particular subject so far seems purely philosophical to me.
I consider it perfectly justifiable to call it physics, but at this level of abstraction, it's hard to differentiate it from religion too.
As long as he doesn't say how people should behave, this isn't religion (even if it relates to how people will behave).
[1]: I.e., assuming a distinction between physical and mathematical
I think that the 'of course' here is not at all obvious. Economics, for example, seeks to describe how people will behave, but neither makes nor, I think, is perceived to offer any description of how they should behave (at least not in any moral sense).
Anyway, even a deterministic universe (mathematical, i.e. monistic Platonistic, or otherwise) is still undecidable/intractable, and so normative prescriptions may well serve an important role as you don't know their place in the causal chain.
Of course, you could argue that "importance" is also a subjective measure in a deterministic universe, and an irrelevant one, but then so is "relevance" itself.
Plus, the faithful themselves were very skeptical of them, and lots of people were charged with impiety for expounding this kind of stuff. Specially so in the case of Spinoza and Kant.