Hello Howard,
Excellent, couldn't agree more with that recommendation. Many CA still have root and intermediate bundles (or individual certificates in their repositories) that are only SHA-1 signed. I intentionally downloaded the G2 versions of the root and intermediate certificates (e.g. from Go Daddy) that has SHA-2 signatures. If not, your chain's essentially not 100% SHA-2. Even with these SHA-2 inclusive certificates, it's possible to still see SHA-1 for the Thumbprint Algorithm but the certificate is signed with SHA-2 and will pass tests (e.g. Google Chrome checks for SHA-1).
Regards,
Michael