Dear Knowledgeseeker98,
I don't think that there is a ready-made migration tool available at the moment.
You need to list down the marketing codes and their timing to fire the event in GTM. Within Adobe Launch, you can directly use the Adobe Analytics Extension to migrate the listed or use the Custom Code (JavaScript) to shift the marketing codes.
What you need to know is, how can you utilize the existing Adobe Analytics Extensions, if not, don't worry, just migrate using Custom Code (JavaScript).
All the tag managers in the world are the same other than changes in the UI, features, and flexibility.
Thank You, Pratheep Arun Raj B | Xerago | Terryn Winter Analytics