I'm just lookng at Imperial Militia because I have a bunch of guys wielding volkite weapons from Armory of Old Night as my Knights' Household Militia, but there are more information here. Take your time, but long story short, new miniatures are on the way, Talons of the Emperor are getting more stuff and their own Liber in time, and Journal Tactica series will be a steady release.
We also get a peek at Mechanicum rules, and unlike the Legiones Astartes Crusade detachments, it seems we get our own unique Mechanicum detachments. So our Primary Detachment will be entirely composed of Archmagos, Magi and Tech-priest Units, which will unlock their own Auxiliary or Apex detachments belonging to their High Tech Arcana.
So I can still build a Legio Cybernetica force by choosing the Cybernetica High Tech Arcana, which will unlock Auxiliary and Apex detachments for automata. Yay.
There are a few hints, like a Macrotek Archmagos getting the Iron Phalanx Apex detachment for three Armor units (Krios tanks or Krios Venators) and three Heavy Transports (the Triaros Armored Conveyor).
Mechanicum units are also cheaper now. Yay?