If I read the patch changes correctly, spaceship parts will now all have to be built in one city. This changes the dynamics and strategy of a spaceship win considerably, and will stretch out the period of building. I have not seen any discussion of this question or criticism of the current rules. Why is the change being made? Not that I think it is a bad idea, just different.
What this change actually means is that two or more cities will no longer be allowed to build the same space ship part. You can have ten cities, each building a different part, but duplication of effort will not be allowed.
I can see why you were misled, as the wording of this change in the text describing the contents of the patch is not worded clearly.