NO. Whatever the Whonix repository , I get this output from update-tobrowser":
## Verifying GPG signature.
## Not using the user's GPG keyring also ensures, that the key can be only
## signed by the GPG keys we added. Signatures from random people from the
## user's keyring will be ignored.
gpg: Signature made Fri 16 Jan 2015 08:28:57 AM UTC using RSA key ID D40814E0
gpg: Can't check signature: public key not found
[ERROR] [torbrowser] GPG download signature could NOT be verified.
Tor Browser update failed! Try again later.
In the host, torbrowser-launcher cannot update either (“SIGNATURE VERIFICATION FAILED! You might be under attack…”).
Installed torbrowser-launcher in two virtual machines, Debian jessie and Ubuntu 14.04, it works. I really don’t know, but I’d like to investigate a little more before wiping the disk.