That's exactly what is likley to happen. How likely I don't really know, but such things have happened before.
Such political "horse trading" is one reason why the protections of the Bill of Rights, including the second amendment, where insisted upon by many state Consitutional ratification conventions. Most didn't hold out for a BoR, but did insist that one be passed and approved the Constitution on the promise that one would be passed. And it was. The only part of what would become the second amendment that was controversial was a provision that would have protected people who were religious pacifists from being compeled to bear arms. The provision was dropped in Congress.