We are committed to providing support for multiple minor versions of Godot at the same time, as long as we have the capacity to do the work and there are fixes that can be safely backported. So even if your project cannot be migrated to Godot 4.1 right now, we still want to share with you some positive changes.
This is a Release Candidate, which means that we don’t expect regressions or new major issues. Please give it a good test if you are currently using Godot 4.0 in your project. Unless a critical problem is discovered, a stable release will follow RC 1 shortly. Remember to always make backups when changing engine version, or better yet, prefer using a version control system, such as Git, to have a safety net in cases of data corruption or loss.