Consolidation Watch: No separate vote for Suburbs on Metro Government?

I recently learned that, at a public meeting, a County Commissioner stated that there is action to have declared "unconstitutional" the requirement that the suburban cities have a right to vote separately concerning "Metro Government"!

(The vote on any Charter proposed by the Metro Charter Commission has to be approved by separate votes by City of Memphis voters and Shelby County voters who do not live in Memphis.)

It should be noted this requirement is part of the Tennessee Constitution, (last paragraph of Article XI, Section 9), so I'm not quite sure how this is "unconstitutional"! If so, perhaps the entire Article on authorizing Metro Government is unconstitutional, if this phase is unconstitutional?

If the scheme is successful, Metro Charter Commission could load the Charter with goodies for Memphis residents (and promises of lower taxes and more services at the expense of County and suburban residents) in the hope that Memphis residents will vote for the new "Metro Government", at great expense to the suburbs and the remainder of Shelby County.

Seems like this may be the reason that separate votes are required!