"s not some nuclear needed anyway if fossil fuels are to be avoided"

No. It's not antithetical to wind and solar in small amounts, but in larger amounts it doesn't play nicely with renewables.

Nuclear is technically and economically inflexible. It needs to run 90% of the time in order to make a profit, and turning most nuclear technologies up and down is slow, if possible at all without causing problems. Further, it needs instant on backup and generation around it that can be shut down in an instant because when it comes onto the grid or goes off of it, it does it in very big chunks. That's much harder to manage than the gradual ramp up and ramp down of wind and solar, which change much more slowly.

Most of the pumped hydro in the world was built to give nuclear something to do at night until recently, as well as some for coal plants.

Wind and solar need firming services. Nuclear needs flexibility services. Some of the firming services, like pumped hydro, overlap, but the operation of them is very different, so trying to provide flexibility and firming with the same grid components adds complexity.

In the USA, the nuclear and natural gas generation industries are strange bedfellows right now because of this. The gas industry is promoting nuclear and nuclear advocates are dismissing concerns about gas. That's because gas is providing the flexibility services nuclear needs in the country.

I would question who is pushing the nuclear story in Australia. It's probably not for the reasons you think. In my experience globally, conservatives love nuclear energy because it allows them to pretend that they care about climate action without actually having to do anything, especially anything about fossil fuels being burned in the next decade.