Hello Blux, and sorry for quite long delay in answer.

In brief, this will not happen. The council membership is meant to be
permanent in the sense that nobody else can force you away from it. This is
handy for example when a group of players have collected the money to create a
city, and they should be mutually equal.

If you (as a city creator) want to be "more equal than your equals", you can
create a city management list with exactly equal rights to real council (i.e.
yourself). In this case the only difference is, that you can give and take
away the rights at your whim.

But the council list will remain as it is. That's the very idea of this
specific list.

Gront