Would you have preferred we didn't make this update?
From a business ethics point of view, you had to do this update though, because in the whole time between 1.4 and 1.7 the DLC "American Dream" was half useless, due to its incompatibility with COP, yet was still being promoted ingame on the menu, and the issue were not mentioned on the steam store or anywhere IIRC.
I think in the future if a feature of a dlc conflict with a feature of another dlc like that, the fair thing to do would be to fix it asap, so that a customer don't end up with features he can't use despite he paid for them in the first place. If you can't fix it or that you think it will take a long time, then at least put a warning out there for future consumers or set up a refund policy or something for the conflicting DLCs.
I know this is more a marketing issue than anything, and has probably little to do with you in particular, but i think the issue over American Dream was real in that case, and there was kind of a lack of information around it, so it's worth discussing.