A compromise isn't necessarily an exclusive lock on posting rights, so the existence of other credible-looking non-controversial posts, after the posts-in-doubt

A compromise isn't necessarily an exclusive lock on posting rights, so the existence of other credible-looking non-controversial posts, after the posts-in-doubt, does not verify the provenance of the posts-in-doubt. I'd wait for a reputable journalist -- someone who actually picks up the phone, or visits SendGrid, and talks to someone there they knew already as a person with corporate authority -- to confirm.