This fear-mongering is going to make JWs even more suspicious of The Superior Authorities™ than they already are. Honestly, I wouldn't be surprised in coming years to see them making hints at 'taking matters into your own hands' to ensure the Organization™ is protected - from Apostates™, from the Disfellowshipped™ and from non-JW family members who refuse to become JWs.
I would be extremely careful around any JW whom I knew to have firearms.