I cannot move broadcast signals to new channel positions at will. I doubt that Congress is willing to grant me the right to make unilateral changes. I am sure the broadcaster would oppose such an idea. This option creates a requirement to move satellite signals as well. They will not take kindly to the notion of unilateral contract changes when their channel is replaced by a broadcast signal.
Subscribers also face higher fees for cable networks, as V-band discounts are lost.
We should not forget the viewer in all of this. Long-established viewing patterns will be disrupted by such a change. Consider the advertisers as well. Local merchants have invested heavily to create a presence on cable networks. Wholesale changes to lineups disturb their significant investment.