Empty shared types seem to be ignored in a Y.Array!?

If you run this code in a browser

  const sharedDoc = new Y.Doc()
  const sharedArray = sharedDoc.getArray('sharedArray')
      null, true, 1.23, 'Test', [ null,true,1.23,'Test' ],
      { 'null':null, 'boolean':true, number:1.23, 'string':'Test' },
      new Uint8Array([1,2,3,4]), new Y.Map(), new Y.Array(), new Y.Text(),
      new Y.XmlElement(), new Y.XmlFragment(), new Y.XmlText(),
      new Y.Doc()

and then inspect sharedDoc.share[1].value._start.content.arr within your browser’s console, you will see only the first 6 elements - the new Y.Map() and the following are missing

Running a similar code for a Y.Map

  const sharedDoc = new Y.Doc()
  const sharedMap = sharedDoc.getMap('sharedMap')
    sharedMap.set('null',        null)
    sharedMap.set('boolean',     true)
    sharedMap.set('number',      1.23)
    sharedMap.set('string',      'Test')
    sharedMap.set('tuple',       [ null,true,1.23,'Test' ])
    sharedMap.set('struct',      { 'null':null, 'boolean':true, number:1.23, 'string':'Test' })
    sharedMap.set('binary',      new Uint8Array([1,2,3,4]))
    sharedMap.set('map',         new Y.Map())
    sharedMap.set('array',       new Y.Array())
    sharedMap.set('text',        new Y.Text())
    sharedMap.set('xml-element', new Y.XmlElement())
    sharedMap.set('xml-fragment',new Y.XmlFragment())
    sharedMap.set('xml-text',    new Y.XmlText())
    sharedMap.set('doc',         new Y.Doc())

will list all entries instead.

Is this really the intended behaviour?