From a cursory (icony?) view, it seems to be missing the ones from moricons.dll, but memory is foggy and it might be that moricons.dll had been dropped by win98. It's been 26 years, wouldn't be surprised to find my memory is wrong.
MORICONS.DLL is still present in current versions of Windows! But (AFAIK) none of the icons were ever updated after Windows 3.1 to conform to newer design standards, so it's reasonable to leave them out of a set of "Windows 98" icons.