You may like to email them directly. I have a couple of times and received a prompt and informative reply from Andreas.
In his last (late Aug) he mentioned that they anticipated 2–3 weeks for the first three mini sets, with the 'normal' sets that are around stage 7 (# 017, # 016, # 030, # 025 and # 018) scheduled after that (no estimated timing for these at that stage).
Naturally, delays are more likely than not at present. They's a coming though!
Hard to tell, but yes I would guess something from the Diadochi eras or later is likely, as I do not think the evidence is good enough for something pre-Alexandrian. Parthian or Sassanian is also possible.