I assume this will be the mini dex with the future release being the full army.
And the Mechanicus still has a standing military force to protect Forge Worlds, as part of Explorator Fleets to recover lost tech, ect.
Well yes they do, but the AdMech in general haven't been a major military power since the Heresy. Most battles involving Skitarii tend to be either them in conjunction with another Imperial force (as support), the defence of a Forge World or as part of an Explorator Fleet. The Legio Cybernetica and the like are (if my information is to be belived) in such small numbers after the Heresy as to be effectively defunct.
Still, I *really* wouldn't get your expectations up. I know my FLGS Manager has. It's kinda heart breaking.