An e-mail subject not being encrypted by PGP should be prominently mentioned

In the Email Security article, an e-mail subject not being encrypted by PGP should be much more prominently mentioned, rather than buried in the Metadata section. Subject is not metadata, it is often a distilled version of the message itself, or at least usually contains significant amount of information. I would expect a big red box in the “Email Encryption Overview”, not a minor mention in the Metadata section.