I'm not sure whether this should be an extension or a core piece of functionality, but should a "sort" key be able to be defined when retrieving data? I think that this may be relatively easy to implement, since a dict is returned, so sorting a dict is straightforward.
Arguments for implementation:
Should be straightforward
Many use cases may be out there
Other JSON-style DBs offer this
Arguments for not implementing:
It's straightforward for developers to do by themselves
It may go against the "keep it simple" approach of TinyDB