No territory, nor any part thereof, which is involved in any proceeding to change the boundaries of a school district by detachment or dissolution from such school district of such territory, and which, after a hearing on the merits of the petition or referendum vote, is not so detached or dissolved, shall be again involved in proceedings to change the boundaries of such school district for at least 2 years after final determination of such first proceeding, unless during that 2-year period a petition filed is substantially different than any other previously filed petition during the previous 2 years or if a school district involved is identified as a priority district under Section 2-3.25d-5 of this Code, is placed on the financial watch list by the State Board of Education, or is certified as being in financial difficulty during that 2-year period or if such first proceeding involved a petition brought under Section 7-2b of this Article 7. The 2-year period is counted beginning from the date of a final administrative decision after all appeal timelines have run, upon final court order after all appeal timelines have run, or upon the certification of the election results in the event of a dissolution. The 2-year period is 2 calendar years.