Is there a difference in how bundles are promoted?
Promoting a bundle works the same as promoting any individual PR. Select the bundle from the open list and click 'Promote', which validates and promotes those features together as a single unit:
Once the bundle is successfully promoted, it opens against the next environment as a single unit. The individual features are not reopened.
Can I change a bundle after it's been promoted?
Once a bundle is promoted, you can remove individual features from the bundle as long as it hasn't been promoted to a downstream environment and fix those as needed.
You can only remove the most recently added features in order. It's not yet possible to remove an arbitrary feature from elsewhere in the bundle.
See our documentation on Add or remove features from your release branch.
Note: It is not possible to remove features from a release that was promoted from a release candidate.