For purposes of this chapter, a "revision" to a municipal charter shall mean any change to an existing charter that results in a change in the municipality's form of government to any of the following forms:
I. Traditional town meeting.
II. Official ballot town meeting.
III. Town council.
IV. Official ballot town council.
V. Budgetary town meeting.
VI. Representative town meeting.
VII. City under mayor-alderman plan.
VIII. City under council-manager plan.
IX. Any other form hereafter expressly authorized by statute.