If the rules are Turing-complete, then sure. I don't see enough in the report to tell one way or another; the way rules are made to sound as if filling templates about equally suggests either (if templates may reference other templates) and there is not a lot more detail. Halting seems relatively easy to manage with something like a watchdog timer, though, compared to a sound, crash- and memory-safe* parser for a whole programming language, especially if that language exists more or less by accident. (Again, no claim; there's not enough available detail.)

I would not want to do any of this directly on metal, where the only safety is what you make for yourself. But that's the line Crowdstrike are in.

* By EDR standards, at least, where "only" one reboot a week forced entirely by memory lost to an unkillable process counts as exceptionally good.