Considering there are people flying around with fleet elite phasers I don't see how you can get more confirmed than "it's already happened".
It was also stated by the devs that Elite Fleet space weapons would be the faction's signature weapon type (Phasers for Fed, Disruptors for KDF). Those even correlate with the ground Elite Fleet weapons.
Originally Posted by astrospider
They are not fleet Elite. They are fleet Advanced.
No there's Elite Fleet weapons out. I've seen them linked in chat. Go to Organized PvP or Doffjobs and ask for someone to link them.