there is a data transfer system! music does have memorization to an extent well, but definitely do not rely on it! it really depends on the transfer process. i was able to change phones (iphone to iphone) easily without having to utilize the data transfer, just by relying on iphone's transfer system.

data transfer is easy to set up (you will save a code & a password), so i would prepare it, and after your device transfer, you can then use it if it is needed. the wiki page has some details on data transfer that might be more clear.

it's usually good practice to obtain a code & password, and then save it somewhere secure without using it! that way if you lose access to your account somehow, you can just input the saved code&pass and regain access!