The area of operation or boundaries of a regional housing authority shall be decreased from time to time to exclude one or more counties from such area if the governing body of each of the counties in such area and the commissioners of the regional housing authority each adopt a resolution declaring that there is a need for excluding such county or counties from such area; provided, that no action may be taken pursuant to this section if the regional housing authority has outstanding any bonds or notes, unless all holders of such bonds and notes consent in writing to such action; and provided further, that if such action decreases the area of operation of the regional housing authority to only one county, such authority shall thereupon constitute and become a housing authority for such county, in the same manner and effect and with the same boundaries, functions, rights, powers, duties, privileges, immunities, and limitations as though such authority were created and constituted a public and corporate body for such county pursuant to this chapter, and the commissioners of such authority shall be thereupon appointed as provided in this chapter for the appointment of commissioners of a housing authority created for a county. The governing body of each of the counties in the area of operation of the regional housing authority and the commissioners of the regional housing authority shall adopt a resolution declaring that there is a need for excluding a county or counties from such area only if: Each such governing body of the counties to remain in the area of operation of the regional housing authority and the commissioners of the regional housing authority find that, because of facts arising or determined subsequent to the time when such area first included the county or counties to be excluded, the regional housing authority would be a more efficient or economical administrative unit if such county or counties were excluded from such area; and, the governing body of each such county or counties to be excluded and the commissioners of the regional housing authority each also find that, because of the aforesaid changed facts, another housing authority for such county or counties would be a more efficient or economical administrative unit to function in such county or counties. Nothing contained in this section shall be construed as preventing a county or counties excluded from the area of operation of a regional housing authority, as provided in this section, from thereafter being included within the area of operation or boundaries of any housing authority in accordance with this article or this chapter. Any property held by a regional housing authority within a county or counties excluded from the area of operation of such authority, as provided in this section, shall, as soon as practicable after the exclusion of said county or counties, respectively, be disposed of by such authority in the public interest.