Windows Sandbox

How does this relate to Application Guard (https://docs.microsoft.com/en-us/windows/security/threat-protection/windows-defender-application-guard/wd-app-guard-overview)? To solutions such as Bromium Virtualization-based Security (VBS) (https://www.bromium.com/our-tech/virtualization-based-security/)?

Bromium's technology is effective, but very expensive.

Application Guard does what Bromium's VBS does, but for Microsoft Edge only.

Is Windows Sandbox a minimum viable product (MVP) in an early sprint to extend Application Guard beyond Microsoft Edge?  If so, I would love to know - and I am 100% certain you cannot and will not tell me - when this begins to offer an alternative to Bromium's VBS.

Microsoft offers Advanced Threat Protection (ATP) products, for example for Exchange Online and Windows Defender.  Has Microsoft taken the detonation sandbox it created for Exchange Online Advanced Threat Protection and packaged it down into a Windows feature called Windows Sandbox?  Will future versions of Windows Defender ATP install and control this sandbox, so they can detonate untrusted .EXE files to determine if they are safe, then report back to Microsoft Security cloud that the unknown .EXE is safe, and share with Office 365 ATP and Windows Defender ATP subscribers?

Is this also a way to "deprecate" WIN32 API?  ISTR WIN32 is great, but is now huge and created for more innocent times.  A modern Windows without WIN32 would be smaller, faster and more secure.  However, if you did still need WIN32 apps, you could run them within the Windows Sandbox.

(forgive the somewhat wild speculation - this looks like a very significant technology, but you haven't explained it fully; I don't buy the "How many times have you downloaded an executable file, but were afraid to run it?" line - I don't accept that's Microsoft's only motives and the full picture).

PS I am simplifying somewhat; eg Bromium is expensive - if you get hacked, it's dirt cheap!  But as a preventative measure, it's expensive).