Really excited about the new Ionic 4.0.0 released. However before I plunge myself into it I would like to wait for the beta phase to be completed. The question I have is when I do ionic serve, it asks if I want to upgrade my Ionic Cli from 3.20.0 => 4.0.0. I am assuming if I do this upgrade my app will break as it will need to be migrated to 4.0.0 standards, is this right?
No. Ionic CLI and Ionic Framework are two different things.
Ionic CLI 4.x supports all Ionic Framework versions, from v1 up to the new v4 beta.
Great thanks for clarifying
Some more information on that by the way: