The pick command for v8 File Picker does not include a file's MIME-Type

[SantiagoUriarte]

   const options = {
      sdk: '8.0',
      entry: {
        oneDrive: {},
      },
      authentication: {},
      messaging: {
        origin: window.location.origin,
        channelId: channelId,
      },
      typesAndSources: {
        mode: 'files',
        pivots: {
          oneDrive: true,
          recent: true,
        },
      },
      selection: {
        mode: 'multiple',
      },
    };
    const queryString = new URLSearchParams({
      filePicker: JSON.stringify(options),
    });

    const url = `https://onedrive.live.com/picker?${queryString}`;

Using these options the return does not include important information such as MIME-Type. This was a feature that was supported in 7.2 via advanced query params like
select=file

Am I missing something or is there no way to get the MIME-Type of the picked file without having to download it?

[SantiagoUriarte]

I see that IItem should include a file key if it is a file but this is missing from all responses. Could be a bug? Is there some special config that needs to happen for this data to be sent over?