[driverdan]

They have a public issue tracker (issues are withheld from public for 90 days): https://bugs.chromium.org/p/project-zero/issues/list

and a blog: https://googleprojectzero.blogspot.com/

and a Github org: https://github.com/googleprojectzero

and their members do tweet about their findings on their personal accounts.

But no, they don't have an official Twitter account.