1. When any city is disincorporated, the board of county commissioners shall at the time of such disincorporation fix the boundaries of the unincorporated town created therefrom, if one is created pursuant to this chapter.
2. If all or any part of an unincorporated town is annexed by any incorporated city, the territory so annexed shall be automatically detached from such unincorporated town at the time of such annexation, and the boundaries of such unincorporated town shall be contracted accordingly, without further action of the board of county commissioners.