If I open my file I see:
<ItemGroup>
<Reference Include="Xamarin.Mac">
<HintPath>..\..\..\..\..\..\Library\Frameworks\Xamarin.Mac.framework\Versions\7.4.0.4\lib\reference\mobile\Xamarin.Mac.dll</HintPath>
</Reference>
<Reference Include="Xamarin.iOS">
<HintPath>..\..\..\..\..\Library\Frameworks\Xamarin.iOS.framework\Versions\14.14.2.5\lib\mono\Xamarin.iOS\Xamarin.iOS.dll</HintPath>
</Reference>
Is this to be expected for the shared file?
No, as various Xamarin.Forms native projects wouldn't compile if they refer to this project.