The problem I see with allowing the altering of the uniforms is that it sets a precedent, and there might be other “sides” of the issue. What if a team wanted to put Black Lives Matter emblems on their uniforms? What if a team decided some gang symbol would be good to represent it?
Nike is the NFL's sponsor for the league's uniforms. You can be sure that their contract has very clear language that restricts what can be added to an NFL uniform.
“What if a team wanted to put Black Lives Matter emblems on their uniforms? What if a team decided some gang symbol would be good to represent it?”
The NFL still has absolute control over everything about players uniforms. The small decal was almost unnoticeable but was strongly supported by the Cowboys. Allowing the Cowboys to wear it would not in any obligate the NFL to approve any other uniform change.