No. What they are saying is the U.S government confiscated guns from the Native Americans, as a result, the Native Americans were defenseless against the U.S. government when it decided to massacre them.
When did that happen? Your just making stuff up now. The Native Americans bought guns and used them to kill colonists and later Americans in lots of bloody engagements. Who sold them to them? First the colonists and then the British to cause the Americans problems. Guns led to the death of more Americans, a common theme through history!