In car manufacturing robots are used to bolt and weld together stamped metal panels, this feels more like someone designing a robot which would be given a flat sheet of metal and using hammer and dollies forming the complete panel to be attached to the car.
In short, if we ever see a major change to automate housing construction I expect it will also come along with significant changes in construction methods.
It's the difference between trying to take the factory to the site and just taking the parts to the site.
Also, as far as I understand, 3D-printing concrete does not give you any way to construct larger buildings, where you need pretensioned and reinforced parts...
Couldn't you just build a tent-like scaffolding for this purpose? Maybe one that can be extended as the internal build progresses?
It is simpler to just put the house there quickly.
Construction is one of those things where the process is much less regular and perfectly-repetitive than outcomes would suggest.
But aren't many of them? May be country specific, but in the one I currently reside there are tons of neighbourhoods that were built at once, 1000 homes+. In the US I've seen areas like that too. I can easily imagine a robot puts down the basics, and the individual tweaking is done later by hand.