I tend to remember that it is not possible to get a status update for a FB Ticket as long as you are not the one (or part of the team) who created the ticket (for obvious privacy and confidentiality reasons).
And based on what I'm reading from some posts in the forum, it's not unusual that a FB ticket declared to be a duplicate of another ticket is not updated when the original ticket is either fixed or closed.
So what is the recommendation to be informed about the status of a problem when you know that a FB ticket was already filed by another party (and it's obvious your ticket will be marked to be a duplicate)?
File a FB ticket on the same topic with a reference to the original FB ticket and pray?
N.B. : this is not a case listed in the https://developer.apple.com/bug-reporting/ page.