Right now the way things work, all Model's are static meshes.  This means that they will not change at runtime.  If we add support for dynamic meshes, then we need a way to define (in tooling) that we promise a mesh will not change in it's lifetime.  This can enable optimizations in the renderer like static mesh batching in some cases.

It is enough to just add the flag to the front-end and backend for this task to be considered complete.