Under the proposal, Mr Wilcox's general manager of news and current affairs role and Ms Hirschfeld's general manager of production are among five roles to be disestablished.
The pair have been offered new roles at the broadcaster although sources at the station say they are a step down from their old positions.
Mr Wilcox is a foundation member of Maori Television and despite moving to his executive role last year after winning Best Presenter News and Current Affairs in 2012 at the New Zealand Film and Television Awards, he has long been seen as the station's "face".
He couldn't be contacted for comment yesterday but a source close to him said he was "completely shocked" by the developments.
The person said staff were also "hugely disappointed" and it was unclear whether Mr Wilcox would put his hand up for a newly created head of programming and production role that will absorb his old news and current affairs job. Ms Hirschfeld declined to comment.
Carol Hirschfeld
Joined Maori Television as head of programming in 2009, later appointed general manager of production. Presented 3 News with John Campbell from 1998 to 2005. Worked in journalism for more than two decades and is an accomplished editor, producer and reporter.
Mr Maxwell said the proposed restructure was necessary to boost performance and results and to align the station's operations with its strategic direction and role as a multi-platform broadcaster.
The station was looking to give a bigger focus and emphasis to Maori language and culture - including a five-year plan to ensure 75 per cent of staff were fluent in Te Reo Maori.
Asked if the changes to executive positions were due to performance, Mr Maxwell cited privacy issues.
"The only comment I can make is all my senior executive team are highly valued for the experience and skills they bring to the table and they have all been retained in the new proposed structure."
He said the proposal was not "change for change's sake" but about future-proofing the station and the proposed changes had been used by some politicians as a political football.
Mr Maxwell also said there were no plans to rein in its editorial department, including its highly regarded Native Affairs show, which drew the ire of some within Maoridom through its critical questioning of the Kohanga Reo National Trust.
"I've been very clear I'm a very big supporter of Native Affairs, I always have been.
"I recognise that we need investigative programming that asks some hard questions of our future collectively as Maori. In the proposed new structure there are no changes in Native Affairs or Te Kaea as speculated - that hasn't happened and won't happen under my stewardship."