Starting Monday, April 18th, we’ll completely freeze the ROS 2 base Rolling branches so we can branch off Humble from Rolling. After the branching is complete, Rolling will become unfrozen - so feature and API changes can be merged into the Rolling branches once again - and I’ll make an announcement on Discourse.
You can find more info on the Humble release timeline here: ROS 2 Humble Hawksbill (codename ‘humble’; May, 2022) — ROS 2 Documentation: Rolling documentation.