FAQ: If I edit a Flow (e.g. if I edit a template that is already being used inside the Flow), does that affect contacts who are already in the Flow?
Any changes that you make to the Steps in a Flow only affect contacts who have not passed that step yet. So, anybody who already received an email, for example, will not be affected if you make changes to the Template for that email step, and any people who have not received that email yet will receive the new Template moving forward!