Why Kochi Corporation never expanded since 1967?

I was surprised to learn that the Kochi Municipal Corporation has not expanded its boundaries since its establishment on November 1, 1967.  It’s astonishing that areas like Maradu, Kakkanad (home to district headquarters and IT and tech companies) Edappally areas (home to Lulu Mall), cheranalloor area and Kalamassery are not part of the Kochi Corporation. This exclusion could mean missing out on various central funds and development opportunities. Why hasn’t the government expanded the corporation limits? Administrative challenges? Political reasons? Lack of local demand? Or any other reason? What about the Metropolitan Planning Committee (MPC) for Kochi? Please let us know your thoughts.