The “scope and breadth” of changes to the NSW roadmap out of lockdown caught the Australian Medical Association by surprise, and may lead to “skyrocketing cases”, its NSW president, Danielle McMullen, has said.

Premier Dominic Perrottet announced some significant departures from the roadmap on Thursday, accelerating plans to reopen the state. When lockdown measures begin to lift from 11 October, 10 visitors will be allowed in homes, not counting children 12 and under – double the limit of the previous roadmap. Perrottet also lifted the cap on outdoor gatherings from 20 people to 30, and increased the cap for weddings and funerals from 50 to 100 people.

Indoor pools will also reopen.

On the Monday after 80% of the eligible population over the age of 16 is fully vaccinated, people will be able to have up to 20 visitors to a home (10 under the previous roadmap), and up to 3,000 people will be allowed to attend ticketed outdoor events (previously 500). Masks will no longer be required in office buildings.

All school students will also now return to on-site learning by 25 October.

“We were happy with the roadmap as it was,” McMullen told Guardian Australia. “We thought it was a careful and sustainable reopening. It’s really important that everyone is vaccinated and that’s why we’re still pushing so hard to really get to that 90-to-93% vaccination target.

“And it is why we were trying to keep sensible restrictions in place, and stage the reopening to allow people some relief in terms of their mental health and also to allow businesses to come back in some form, but also to give us a chance to pause and reflect at each stage of the reopening and make sure that we’re keeping people as safe as possible.”

McMullen said she was concerned people might take the accelerated easing “as a sign that they don’t need to worry at all”.

“And then we may see a skyrocketing of cases, and then a need to put back in place more significant restrictions. We certainly don’t want to have to see the community go backwards.”

She said she was particularly concerned about easing of mask restrictions, and the increase in household visitors, given household transmission is a major driver of spread.

“So far we’ve had confidence that the health officials have been in discussions,” she said.

“What we want to continue to see is the real focus on that advice from health, so from [NSW chief health officer] Dr Kerry Chant and her team. Today’s announcements were broader than expected and concerning given we have seen such a shift before we have reopened at all. We would have preferred to give the existing road map a chance.”

Chant was not present when Perrottet announced the revised roadmap.

Epidemiologist Prof Mary-Louise McLaws said she was worried about how the new roadmap would impact the most vulnerable, including those who are immunocompromised and for whom the vaccines are not as effective, and those who can’t get vaccinated for medical reasons. She is also concerned about the impact on young people, since they are driving infections.

“Schools will open up in 18 more days and that’s not quite enough time for all the under 40s to get fully vaccinated,” McLaws said.

“I feel as an epidemiologist with outbreak experience that this new roadmap has not been dictated by the obvious epidemiology. That is, we know there is vaccine inequity. There seems to be this idea that NSW is homogenous. But it’s not. The young, the vulnerable and immunocompromised, and the culturally diverse may not yet be quite fully vaccinated yet at the same rates.”

A professor of epidemiology at the University of Sydney, Alexandra Martinuik, said she believes masks need to stay for the time being, that indoor ventilation needs greater attention, and that capacity limits in venues and households need to be lower.

“Now is not the time for accelerating NSW reopening,” she said. “We are sitting at about 59% of the total population of NSW having two doses of a Covid-19 vaccine. Countries which have re-opened gradually have typically been at 70-80% total population vaccinated.”

Martinuik said the reopening will disproportionately impact the unvaccinated including children, those in regional and rural communities, as well as those people for whom the vaccine may not be as effective such as elderly people.

“We will see an increase in the number of Covid-19 cases in NSW,” she said.