I’m very familiar with oss-security, a public mailing list that doesn’t really have anything to do with GPG-encrypted emails. Encrypting emails to a public mailing list, with GPG or otherwise, wouldn’t really make sense.
> Only use these lists to report security issues that are not yet public
> To report a non-public medium or high severity 2) security issue to one of these lists, send e-mail to distros [at] vs [dot] openwall [dot] org or linux [dash] distros [at] vs [dot] openwall [dot] org (choose one of these lists depending on who you want to inform), preferably PGP-encrypted to the key below.
Yes, that would be an example of LARPing security. The obviously indicator is that encrypting your message is entirely optional, per their own instructions. The less obvious bit is that even if you encrypt your message, anyone without GPG configured who replies has stripped any attempt at encryption from the contents.