This is the only thread I've found with any detailed information on this matter, so I'm going to post here.
Most of the discussions above involve communication between 2 feature classes. I'm trying to go one step further and have 3 feature classes communicate. I have feature classes A, B, and C. A has a forward relationship with B, B has a forward relationship with C. The goal is to have attribute updates in A force attribute updates in B, which in turn force attribute updates in C.
I have one class extension on feature class C that implements IRelatedObjectClassEvents2 RelatedObjectChanged, which listens for changes in feature class B. When I manually make an update to feature class B, as expected, the correct updates are made in feature class C. So that part is working.
Likewise, I have a class extension on feature class B that implements IRelatedObjectClassEvents2 RelatedObjectChanged, which listens for changes in feature class A. Also as expected, when I manually make updates to feature class A, the expected changes are made on feature class B. So this part is also working.
The problem I run into is that when I manually update Feature Class A and Feature Class B gets updated, the extension on Feature Class C doesn't fire the RelatedObjectChanged event. As a result, my updates to feature class A aren't cascading all the way to feature class C.
What am I missing that is causing the event to not fire on feature class C?