They're all half siblings. They'll definitely be plagued by low genetic diversity and will have higher rates of genetic disease and stillbirth but the species should be able to make it through that with careful management
We can guess it is not going to be the same mothers, so that risk should be reduced quite a bit. Most are all half-brothers and half-sisters, unless from same litter.
Otherwise there would be a hero mom who gave birth to 800 kids.