Yes, it's possible to migrate from non-real-time collaboration features to real-time collaboration in CKEditor 5. This involves migrating your existing data to align with the requirements of the Real-time Collaboration service and then configuring the editor with the necessary plugins.
You will find instructions on how to do it in a dedicated guide. You can also learn more about CKEditor 5’s collaboration features and their real-life implementations in this dedicated blog post.