The <x id="START_LINK" ctype="x-a" equiv-text="<a class="link-orange" routerLink="/about/peertube" fragment="privacy" target="_blank">"/>sharing system<x id="CLOSE_LINK" ctype="x-a" equiv-text="</a>"/> implies that some technical information about your system (such as a public IP address) can be sent to other peers, but greatly helps to reduce server load.
This is an <x id="START_TAG_STRONG" ctype="x-strong" equiv-text="<strong>"/>import<x id="CLOSE_TAG_STRONG" ctype="x-strong" equiv-text="</strong>"/> tool and not a migration tool. It's the reason why data (like channels or videos) is duplicated and not moved from your previous PeerTube website.