My notes on the path to this update show:
- Added a Bluetooth icon to the status bar
- Turn on Bluetooth after waking up device from sleep to establish a quicker reconnection to BT devices
- Improvements to the update process to help prevent devices from getting stuck
- Updated certs
- Improvements to WiFi and Bluetooth stability
- Fixes for some upgrade guardrails
- Stability improvements
- Improvements to BT stability and reconnection on entering a book
AFAIK, this update will propagate to the other Kobo devices starting with the Bluetooth enabled devices and moving back to older devices. Many of the changes are related to upgrade issues though the Bluetooth changes seem more related to the new pageturner reconnecting after sleep.