Windows VS (Visual Studio) 2019 is the default/current distro version supported by Evergreen (windows-vsCurrent), at the time this ticket is written. We should switch to using it (windows-vs2019) from windows-vs2017 at some stage.
We recently ran into a git checkout issue under the Cygwin environment (WT-10006), which is expected to have a much lower chance to hit on Windows VS 2019. It could be a reason to push the upgrade effort forward if the issue starts to hit more frequently on VS 2017.