Earlier quoted context omitted.
pnpm just added this: https://pnpm.io/blog/releases/10.16
This sounds nice in theory, but does it really solve the issue? I think that if no one's installing that package then no one is noticing the malware and no one is reporting that package either. It merely slightly improves the chances that author would notice a version they didn't release, but this doesn't work if author is not particularly actively working the compromised project.
And I agree that if everyone did this, it would slow down finding issues in new releases. Not really sure what to say to that... aside from the selfish idea that if I do it, but most other people don't, it won't affect me.