I have read abou this earlier today, and there's now a page on the Chorus website: Introduction of a new ONT.
Due to global supply challenges arising from the COVID-19 pandemic, we have become aware of significant risk to our ongoing supply of the current 3rd Generation ONT.
We are proactively working with our partners at Nokia to secure a supply of an alternative ONT which matches or exceeds the key features of the 3rd Gen ONT. We can now confirm that we have agreed to deploy a new 4th Gen ONT (Type 400) as our new standard ONT for all NGA connections. We will continue to deploy Hyperfibre ONT for Hyperfibre connections."
Adoption is predicted for April to June 2022. More details on the link above.