The question arose when users realized that in order to use VirtualBox, they must have Hyper-V. But in order to have Hyper-V, you must have Windows 10 Pro installed on your PC.
This is because neither Hyper-V nor Windows Sandbox are available in Windows 10 Home.
As you may know, both Windows 10 version 1803 Pro and Windows 10 version 1803 Home are among the Windows 10 versions that received the May 2019 Update, along with Windows 10 version 1803 Pro for Workstations and Windows 10 version 1803 IoT Core.
As far as program functionality goes, it was a well-known fact that Hyper-V and older versions of VirtualBox could operate simultaneously if Hyper-V was enabled.
However, it would seem that all that will change, as Windows Insiders stated that:
Security features coming in future versions of Windows require Hyper-V to be enabled, and because of that VirtualBox 6.0 introduced the ability to use Hyper-V as the backend. This December 2018 update allows the 3rd party virtualization tool to now support Hyper-V as a fallback execution core on a Windows host.
This means that now both programs can run at the same time, just that Hyper-V will be in the backend.
Taking all of the above into consideration, it would seem that there shouldn’t be any problem with users having VirtualBox and Hyper-V after applying the Windows 10 May 2019 Update.
In fact, the only thing users should be careful with is using the latest version of VirtualBox, and having Windows 10 Pro or Windows 10 Pro for Workstations as the running OS.
You may also want to check out these Windows 10 May 2019 Update posts: