[Client] You're supposed to keep your highest rank right?

https://i.gyazo.com/26f5ac276db29a8cb3f8755e6908aa8b.png I remember reading somewhere that we're supposed to keep our rank. A lot of people did. One guy was gold with negative 45 LP so I assume so.

https://i.gyazo.com/cae91e7a637c09f5ff340a29ca876882.png And, unfortunately, this is the only pic I found where it has my profile name and (previous) rank in one picture. Was silver 3 79 LP last.

Though I'm unsure if we were supposed to keep our rank, because I have literally no idea where to find this information. There's no consistant place where Riot posts info, sometimes it's on the boards, sometimes on the subreddit, sometimes on Twitter. No idea because I follow none of these sources.