"Our Northland disabled community is mostly Māori and many are poor or living in remote communities."
However, the Government assured there would be support for "members of our community who are not digitally enabled" as well as "clinical care and welfare support".
But McMillan indicated there had been unanswered issues of accessibility and Covid before the arrival of Omicron.
He said the promised support to replace unvaccinated staff had "never been successfully implemented".
"Caregiving and support services have collapsed for many disabled due to the high number of people not wanting to be vaccinated. Many disabled people, including me, lost our support workers.
"Many disabled are likely to become housebound if Omicron causes the support worker system to collapse further than it already has."
Jonny Wilkinson, chief executive of the Tiaho Trust, which provides services and advocacy for disabled Northlanders, said there was the "potential for further isolation of an already isolated cohort" due to the digital divide being mixed with the Omicron response plan.
He said Northland has a "relatively low" amount of connectivity related to data and broadband - let alone whether people have the technological capability or knowledge of digital devices.
"The disabled community, the older community, the rural community, I think they will be impacted through the digital divide. Three different cohorts."
Wilkinson thought the system sounded "a bit automated" and feared important messages would get missed by the most vulnerable people.
"Is there enough confirmation mechanisms involved to know that they [disabled people] are going to get the message and they can respond appropriately?"