Apple has increased the Boot Camp version to 6.1.17. The software package that is required for Windows on a Mac now receives support for the new Apple Studio Display and new AMD drivers (via reddit).
This means that the new 5K 27″ display and current AMD graphics cards can also be used under Windows.
If you use Boot Camp and are of an experimental nature, you can also check out this page. There are unofficial drivers for Boot Camp installations available that may lead to higher performance of the supported graphics cards.