This all looks awesome!
If we're to expect a new campaign for the release (which looks likely when looking at the last Primaris waves), perhaps it could be one against mortal Slaanesh forces (House Devine being one of the better known Chaos Houses), and Iron Hands vs. Emperor's Children would be very thematic!
Regardless, the Iron Hands character looks pretty great imo, and super happy for my AdMech player friends that they'll be able to get some new stuff too
IH vs EC would be very interesting. For one because of their Primarch but also because of what they represent. The ones who don't want to feel anything vs the ones who want to feel everything. Also two colour schemes with good contrast if GW doesn't go with the mostly black and only few pink details for EC. ^^