While I agree, it makes connecting to localhost as easy as http://0:8080/ (for port 8080, but omit for port 80).
I worry that changing this will cause more CVEs like the octal IP addresses incident.
Edit: looks like it’s only being blocked for outgoing requests from websites, which seems like it’ll have a much more reasonable impact.
Edit 2: skimming through these PRs, at least for WebKit, I don’t see tests for shorthand IPs like 0 (and no Apple device to test with). What are the chances they missed those…?