fasttrack.debian.net has a limited scope. It’s really awesome, livesaver for Whonix VirtualBox but not a magic bullet by any stretch. Since gnupg doesn’t have any issues requiring it being uploaded to fasttrack.debian.net I don’t think it will ever be added to fasttrack.debian.net. fasttrack isn’t going to succeed Debian backports in speed. To verify gnupg being unavailable in fasttrack, web search term:
site:fasttrack.debian.net gnupg
At time of writing, gnupg doesn’t seem to be available in Debian backports either.