This doesn't seem to be the case. On the latest Windows 10 I tried out this test...

This doesn't seem to be the case. On the latest Windows 10 I tried out this test program

  HANDLE file = CreateFile(TEXT("\\\\.\\C:\\mmap.bin"), GENERIC_ALL | SYNCHRONIZE, FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, NULL, OPEN_ALWAYS, 0 /*can also try: FILE_FLAG_DELETE_ON_CLOSE*/, NULL);
  if (file != INVALID_HANDLE_VALUE)
  {
  	HANDLE mapping = CreateFileMapping(file, NULL, PAGE_EXECUTE_READWRITE, 0, 1, NULL);
  	void *ptr = MapViewOfFile(mapping, FILE_MAP_ALL_ACCESS, 0, 0, 0);
  	CloseHandle(file);
  	*static_cast<unsigned char *>(ptr) += 1;
  }

with /NXCOMPAT and even /DYNAMICBASE and with the embedded manifest

  <?xml version="1.0" encoding="UTF-8" standalone="yes"?>
  <assembly manifestVersion="1.0" xmlns="urn:schemas-microsoft-com:asm.v1" xmlns:asmv3="urn:schemas-microsoft-com:asm.v3">
  	<assemblyIdentity type="win32" name="Microsoft.Windows.Foo" version="1.0.0.0"></assemblyIdentity>
  	<trustInfo xmlns="urn:schemas-microsoft-com:asm.v3">
  		<security>
  			<requestedPrivileges>
  				<requestedExecutionLevel level="asInvoker" uiAccess="false"></requestedExecutionLevel>
  			</requestedPrivileges>
  		</security>
  	</trustInfo>
  	<compatibility xmlns="urn:schemas-microsoft-com:compatibility.v1">
  		<application>
  			<supportedOS Id="{8e0f7a12-bfb3-4fe8-b9a5-48fd50a15a9a}"></supportedOS>
  		</application>
  	</compatibility>
  </assembly>

but it seems to still modify the file after closure even after the CloseHandle call.