According to Tails official documentation[1], and considering the scenario mentioned by you, you are free to choose if you want to keep your Persistent Storage or if you want to clone the other device Persistent Storage. See please section "4/4 Upgrade your Tails by cloning" of the mentioned URL and you'll see the available options during the upgrade stage:
I had read that documentation from Tails. The doubt came when I talked to some friends and said some things may be changed according to the configuration of the usb with the latest version of Tails.
Thank u!