Archbishop Costelloe led the first speech for the Formation Day for the Archdiocesan Assembly, drawing upon the experience of the Fifth Plenary Council of Australia, and his role as President, in speaking about What is a Diocesan Assembly and the recommendations of a Diocesan Pastoral Council.

Formally launching the 2023-2024 Diocesan Assembly on behalf of Archbishop Timothy Costelloe SDB, Episcopal Vicar for Education and Faith Formation the Very Rev Fr Vincent Glynn explained that convocation of the Assembly comes out of the recent Plenary Council held by the Church of Australia in 2021 and 2022.