MFAT said today that a regulation change in Australia last year meant the law would not expire.
"This update preserves the policy settings relating to New Zealand citizens covered by the 2001 transitional arrangements", the ministry said.
Earlier today, Victoria University researcher Paul Hamer, who has a special interest in New Zealanders in Australia, said he would be "extremely surprised" Australia did not roll over the law change.
He said failing to do so would be "worse than what happened in 2001", when a policy change meant New Zealanders had to get permanent residency before being eligible for citizenship, and access to unemployment, youth and sickness benefits was removed for those on Special Category Visas.
"That was signalled quite a way out, and the rights of people already there were preserved," Hamer said.
"This would be retrospectively taking rights back off people and it would be a really low mark in New Zealand-Australian relations if it happened."
Not extending the law would create a level playing field for all expats in Australia, Hamer said.
"But it would be an abrogation of the rights of Kiwis. In 2001, the people who were already there were protected."
About 200,000 New Zealanders were believed to be living in Australia before 2001. Hamer said about 40 per cent had since secured citizenship.
A spokeswoman from the Australian Department of Immigration and Border Protection did not directly answer Herald questions about whether the law would be extended.
She simply said the Australian Government "has no intention of altering the policy settings relating to New Zealand citizens".
Fears about a change were raised by Morgan Blake, a researcher behind a Facebook page called Protecting Special Category Visa Holders.
He said it was possible the law would be replaced with something entirely different. Ripping protections away without any warning would be underhanded, he said.
New Zealanders who moved to Australia after the February 2001 cut-off must apply for permanent residency, which is capped, and compete against other skilled migrants.
However, Australian Prime Minister Malcolm Turnbull announced last year that the rules would be loosened for some post-2001 arrivals who met certain income thresholds.
Expats who earned A$53,000 ($57,000) over five consecutive years between 2001 and today would eventually be able to apply for permanent residency and later apply for citizenship.