Nothing to do with morphs. A geometry definition consists of two parts: a geometry definition in xyz space and a texture definition in uv space. To color the n-th polygon of the xyz space Poser uses what it finds in the n-th polygon in uv space.

When remapping you swap the definition in uv space with a new one.
Problem is that in a .obj file the definitions are partly mixed. You cannot distribute the part you made new (the uv space definition) without giving also the xyz space definition the maker is so peculiar about.

It was considered there is no objection to give someone something he already has. The key to unlock the information that is to be protected is a copy of exactly that information itself.

A morph just contains information about relative translations of vertices. The only information about the original geometry it contains is the number of xyz vertices used.