We logged an IR (Incident Report) and got a working as designed.
We pushed and it's now an enhancement request.
My advice to those wanting this functionality back is to their own IRs to GTAC and ask to reference the ER number 2237169.
Here's the information we got in response to our questions:
The problem where Replace component for drafting reference component not possible has been investigated and the following has been found.
Drafting Components are not real components and not part of the product structure; therefore, they should be treated as such for all practical purpose. They are special components intended to be used only by the drafting application to facilitate the creation of views of parts and were not designed to participate in the full offering of operations that standard Assembly Components do. Replace Component was not designed to support Drafting components and the execution thereof will lead to unwanted results and unintended consequences. The fact that Replace Component was allowed up until nx853 was due to an oversight and allowing it to remain in its current state will ultimately result in errors and poor quality for many customers.
That said, the decision was made to consider this for a future release. There are far too many issues with this functionality to simply re-enable as is. Proper analysis, design and testing are required in order to support these workflows if this is something we want to provide in the future.
Anthony Galante
Senior Support Engineer

NX3 to NX9 with almost every MR (18versions) plus the NX10 Beta