Reading the text of the law makes me pretty certain. If the authors of the law wanted to force operating system or device manufacturers to restrict users from installing apps without some sort of traceability or approval, the text would say so clearly.

Google’s own statements about the policy are also a factor. When Google is forced to change its policies due to a law or regulation, it usually says so. Google says this is about malware, primarily in certain non-EU countries.

Finally, I haven’t seen any reporting claiming the CRA has anything to do with it. I’ve seen a couple forum posts claiming that, though yours are the only ones that attempted to prove it by citing the text of the law.