There are a lot of qualifiers on this: Only in Singapore, only on apps requesting certain permissions frequently used by scams, and only when downloaded via certain paths.
I don’t see the full details but this implies that it’s still possible for advanced users to side load whatever they want. They don’t want to make it easy for the average user to start sideloading apps that access SMS permissions or accessibility controls.
If it takes a few extra steps for the advanced user to sideload these apps that’s not really a big infringement on freedom like this purism PR piece is trying to imply. Unfortunately sideloaded apps are a problematic scam avenue for low-tech users.
> The move, developed in partnership with Singapore’s Cyber Security Agency, is designed to prevent fraud and malware-enabled scams.
This explains why it’s only in Singapore for now.