Preventing invalid entity state that contains two related collections
I would give these the same signature  

public void IncludeList(Guid id)  

public bool RemoveFromIncludes(Guid id)


And rename  

public bool AddToIncludes(Guid id)
{
    ...
    return _includedLists.Add(id);
}


Another approach is  

Dictionary&lt;GUID, bool&gt;


and just one list