This actualy makes sense for a bad idea change. Last thing anyone needed was more Rangers on the field. One strong CQC squad to break some defenses was ideal, no need for changes there. Their cost was justified too. These are some changes just for the sake of changes.
I repeat my idea for balance team:
Use unique Ranger skin from game files, apply your changes to that squad, add it to new commander under new name. Leave heavy cav Rangers as they are.
I am not actually defending the changes I am simply answering your question why they removed the damage modifier.