It can be hard to accurately predict the timeline for some of these features. The ODK team needs to balance their time with factors such as availability of funding and the potential impact on the large community of users that depend on the software. The developers need to consider how changes will be maintained, avoid breaking changes for users, etc. Changes to enable new data collection workflows will occur across several versions.
You can learn more about what's happening in the Releases forum category and on the Roadmap on GitHub. Also, there is a helpful aggregation of the many discussions regarding entity-based data collection: