For more information about the schema extension have a look into the documentation.
There is a Slack channel #ext-schema on typo3.slack.com for questions, suggestions, feedback, etc.
The schema.org vocabulary is evolving, approx. every 2-3 months a new version is released. The TYPO3 extensions are updated when changes are made to the according vocabulary. The classes for the type models and view helpers are generated by the schema-generator library.
This extension uses semantic versioning which basically means for you, that
- Bugfix updates (e.g. 1.0.0 => 1.0.1) just includes small bug fixes or security relevant stuff without breaking changes.
- Minor updates (e.g. 1.0.0 => 1.1.0) includes new features and smaller tasks without breaking changes.
- Major updates (e.g. 1.0.0 => 2.0.0) breaking changes which can be refactorings, features or bug fixes.