Pretty sure that concrete construction here in Cali must include rebar... it has to be able to survive a big earthquake.
I suspect when the technology is ready they’ll incorporte alternative reinforcing materials such as something like nylon mesh or even kevlar if needed. Something that can be co-extruded at the time of construction. I like the printed concrete idea myself, it’s really a small step from pumped concrete work that’s been done for years.
I don’t see any rebar in the pics but maybe they can integrate it. Not sure.