Packaging fails when nativized blueprint implements interface with virtual function

If an interface contains a virtual function that returns "nullptr", If an interface contains a UFUNCTION that has a TSubclassOf type as a parameter or return value, implementing the interface in a blueprint class that is nativized causes packaging to fail when Nativization Method is set.

Regression:
Yes - Issue does not occur in 4.15.2 Binary (CL 3416026)
No - This issue can also be reproduced in 4.15.3.

1. Download and Unzip attached project
2. File->Package Project->Windows->64-bit

Result:
Package attempt fails

Expected:
Game packages with nativization set.

Nativize blueprint fails with C++ interface