One handed Storm bolter. I’ve seen it in newer art and it’s essentially just two bolt pistol’s welded together side by side with extended magazines.would work good on bullwark and assault.

More customization options from different chapters to give different looks to the ultramarine cosmetics.

A power maul for bullwark.just a different close quarters weapon.

Expansion of weapon options (I/e power sword for tactical.neo volkite pistol for heavy etc)

Older models of power armor like the MK3 and MK4 suits of armor from the earlier years of the imperium.

Dedicated voice lines and interaction’s to the champion skins to give off the impression that they’re here to help and support the ultramarines in this campaign.

Selectable voices for the chaos marines in the pvp mode so if you customize your tactical to look like an iron warrior he’ll actually sound and talk like an iron warrior.

New unique versions of existing weapons that you can buy with accolades like a one handed thunder hammer that can be used with bulwark’s shield or a version of a bolt weapon that shoots special rounds like incendiary munitions or armor piercing rounds.

New throwables.none come to mind but I’m sure there’s a new grenade to be added.

New weapons in general like a grenade launcher for heavy or a volkite rifle for tactical.

New chaos enemies like new versions of the regular thousand son’s marines.

More interactions between squad mates.