No, there is no such flag in 5.7. Nested entities will only have the ID populated. I suspect you may have been using an unsupported method for getting exception events in 5.6 which may have had these properties populated.
We refer to this model as our "Building Block" approach to the API. You can see a detailed explanation in the SDK documentation: https://my3.geotab.com/SDK/default.html#/concepts under "Building block approach". You will need to make 4 calls but you can avoid overhead of 4 separate calls by using a "Multicall". You can find a detailed description in the documentation using the same link under "Multicall".