As per discussion on https://github.com/wagtail/wagtail/discussions/7732, the changes in the upcoming release (sidebar redesign, removal of hallo.js, module reorganisation) warrant a version bump to 3.0 if we're following semantic versioning.
Add system check for use_json_field in StreamField
Change system check level to Warning
Add use_json_field argument to StreamField in test models
Use RemovedInWagtail219Warning instead of a system check
Handle unpacked values in to_python when use_json_field is True
Duplicate models and tests for JSONField-based StreamField
Add basic tests for JSONField-based StreamField
Add json_field property in StreamField to unify JSONField usage
Add docs
Don't use destructuring for kwargs in deconstruct
Add versionchanged note to StreamField reference
Currently, the label shown for a StructBlock's collapsed representation takes its content from the first sub-block of the StructBlock, which isn't always what you want. Add a new `label_format` meta option to StructBlock to allow customising this - e.g. `label_format = "Profile for {first_name} {surname}"`
Matt Westcott