Cross project predecessor completion to force an "update" in dependent project

Description - The project timeline only instantly updates when you manually recalculate the timeline of the project OR when an update is made to the project. So when a cross project predecessor is completed, it more or less doesn't signal the dependent project that a change has been made until the dependent project updates based on a separate criteria. Why can't we add a simple functionality to update project 2 when the task in project 1 is completed or updated? 

Honestly, if cross project predecessors are made available to customers, they should probably have the same functionality available as normal single project predecessors. Right? 

- Jaxon