It is very interesting although I didn't really understand the 'security' part. The motivation seems to be twofold - some bad things have happened because of compromised npm packages and v8 happens to have a robust sandbox. This sounds like a solution looking for a vaguely defined problem. The illustrative example he gives is 'malicious linter'. Is malicious linter that important a threat?
In the example the linter itself is not malicious, but used to deliver a malicious program that can have unrestricted filesystem access. Not vague at all, see recent news on the ‘event-stream’ package being used to steal cryptocurrency wallets.
