Is it normally for Apple employees to ask to log out of iCloud (and disable find my) for repairs?

My MacBook needed repairs and the employee asked to log out of iCloud. I did and when I got my laptop repaired and back, I now have two MacBooks registered on my account in the Apple Store. They replaced the logic board, but I wondering about the old logic board and I am wondering if logging out of iCloud was necessary and if I can trust them with my old logic board and if they can access personal data on there?