I still thing we should release the latest preview as @latest also, since people getting started with the new @babylonjs/* will probably install it without adding the tag.
Then when we release 4.0.0 we can start using @latest - stable release with semver @next - a beta or alpha but a “stable” version @nightly - could be in an instable state, but should could be built and published by a CI
How do we publish to npm today?
CI based?
Script based?