I have multiple projects and many teams working on sprints.
To coordinate a release we've been using a label value and putting values like November_release, then I can run a JQL and see all items related to a release group.
What we've also used is a add-on called pivot report.
This gives an overall effort widget. What is interesting is we've seen the original estimate value inflate from an original estimate of 2500 hours a few weeks ago to now nearly 3500 hours.
How can I show management the places where the work increased... or do a diff to see things from 2 weeks ago to current?