Evergreen appears to be HRC in the newly made available Justice Watch FOIA emails.
In the screenshotted email it mentions three recipients, one of them being "evergreen". Then in the salutation it has HRC and two others listed in the "to" line.
There are thirteen mentions of "evergreen" in this batch of emails.
https://www.judicialwatch.org/document-archive/jw-v-state-hrc-emails-00687/