How would Microsoft destroy win32 platform?

I never mentioned curated stores being the only way to access content.

Microsoft will do what is best for Microsoft. I think that is most likely to be :

  1. Continue to push the Windows Store as the primary means of accessing content for your average consumer, so that their Windows experience starts to compare favourably with the one they’ve got used to on their smartphones.

  2. Continue supporting Win32 and allowing non-Store UWP installs to keep their ‘power user’ customers happy.

Not supporting Win32 and allowing UWP sideloading would kill the platform dead so fast I don’t see any of it ever happening. In the unlikely event it did happen they would lose all developer support and Linux might become a truly viable gaming platform at last and I’d happily switch at that point.