Check out the 9 minute/21 second mark for details:
[…] Those are just things that are in the data files that we didn’t ship with the House of Wolves; they’re not there for you to go look for.
Will these weapons be introduced in the future? Maybe. 347 certainly seems like it’s ready to go.
Currently only 1 person has access to FoAF, you can learn more about it here: