Q: Not sure exactly how to perform Step 4 above "recreating the iTunes library" and exactly why it is important for me?

I have successfully moved/migrated my iTunes from my old MacBook to my new MacBook.  I am now trying to follow the steps in section "After you transfer your library"...specifically Step 4.

How to move your iTunes library to a new computer - Apple Support

I think I understand this step to primarily be done to make sure your iOS devices do not continue to attempt to connect and sync to the iTunes on the old MacBook....is that correct?  If so, I do not understand how the article it points to actually corrects that.

If you don't see your content after you update iTunes - Apple Support

The article seems to be talking about recovering an iTunes library when the current one is "corrupt".

I do not plan to use my old MacBook to sync any iOS devices.  I want all my iTunes management and iOS syncs and Apple TV communication to be occurring on my new MacBook going forward.  Is another alternative to simply uninstall iTunes on the old MacBook and then reinstall?

Thank you in advance for any help/advice