Sigma currently sells a 60-600mm lens for Nikon F and Canon EF (for about 2000 Dollars/Euro here on Amazon). According to a very reliable Japanese source Sigma will announce a new 60-600mm F4.5-6.3 DG DN OS lens in early 2023. This will be available for L and E-mount for sure. But this might also come for the Nikon Z-mount which would be a first for Sigma!
I also guess that it will have a new optical design and not be a copycat of the current existing lens.
There is yet no info about the pricing and exact release date, btu stay tuned for more!