A question moved from one SE site to another. When the question moves does that automatically subscribe you to that other SE site?
BTW, how does one know when his question is moved from one site to another?
No, migration does not automatically create a profile on the new site. If the user is not yet registered there, the question will show as being from an anonymous user until the owner creates a profile on the new site. Once registered, the question will be automatically attached to their new profile.
Users are notified via the global inbox when one of their questions is migrated to a new site. If they are subscribed to receive emails about unread inbox notifications, they may also receive that information in an email if they never checked the site in the meantime.