As of 16 Mar 2021. Taken from the Discord source code

Discord Loading Messages.json

{
  "LOADING_LINE_1": "Discord was almost called Bonfire before we picked our name. It was meant to be nice and cozy.",
  "LOADING_LINE_2": "Discord was almost called Wyvern before we picked our name. Not too proud of that one.",
  "LOADING_LINE_3": "Our logo's name is Clyde.",
  "LOADING_LINE_4": "There are a bunch of hidden \"Easter Eggs\" in the app that happen when you click certain things...",
  "LOADING_LINE_5": "Discord started as a game company making a mobile game called Fates Forever.",
  "LOADING_LINE_6": "Discord’s official birthday is May 13, 2015.",
  "LOADING_LINE_7": "We came up with the idea of Discord Nitro over morning breakfast potatoes.",
  "LOADING_LINE_8": "Our mascot, Wumpus, was originally created as a character with no friends :(",
  "LOADING_LINE_9": "In Discord's early days, light theme was the only theme. Dark theme didn't arrive until August 2015.",
  "LOADING_LINE_10": "In the ancient days, Discord started as a browser-only app.",
  "LOADING_LINE_11": "Our HypeSquad program has three houses you can be sorted in to by taking the in-app quiz: Bravery, Balance, and Brilliance.",
  "LOADING_LINE_12": "The character on our 404 page is a robot hamster named Nelly.",
  "LOADING_LINE_13": "You can play our version of the Snake game on our 404 page by pressing a ~secret~ button.",
  "LOADING_LINE_14": "There's a very small—and we mean small—chance you can get a secret ringtone when calling someone. Good luck!",
  "LOADING_LINE_15": "Our old Partner mascot was an elf named Springle. He recently retired.",
  "LOADING_KEYBIND_TIP_1": "$[](quickSwitcherHook) to quickly find a previous conversation or channel.",
  "LOADING_KEYBIND_TIP_2": "$[](markUnreadHook) a message to mark it as unread.",
  "LOADING_KEYBIND_TIP_3": "$[](markServerUnreadHook) to mark an entire server as read.",
  "LOADING_KEYBIND_TIP_4": "$[](navigateUnreadHook) or $[](downHook) will navigate between unread channels",
  "LOADING_KEYBIND_TIP_5": "Use $[](keyboardShortcutsHook) to bring up the list of keyboard shortcuts.",
  "LOADING_KEYBIND_TIP_6": "$[](messageNewlineHook) to make a new line without sending your message.",
  "LOADING_KEYBIND_TIP_7": "Holding $[](shiftHook) while clicking emoji allows you to send multiple emoji.",
  "LOADING_KEYBIND_TIP_8": "You can press $[](upHook) to quickly edit your most recent message.",
  "LOADING_TIP_1": "You can use Streamer Mode to hide personal details while streaming.",
  "LOADING_TIP_2": "You can type /tableflip and /unflip to spice up your messages.",
  "LOADING_TIP_3": "Characters like @, #, !, and * will narrow Quick Switcher results.",
  "LOADING_TIP_4": "Click a server name in the emoji picker to hide that server's emoji.",
  "LOADING_TIP_5": "Hover a GIF and click the star to save it to your favorites.",
  "LOADING_TIP_6": "The top-most role for a user defines that user's color.",
  "LOADING_TIP_7": "A red mic icon means that person has been muted by a server admin.",
  "LOADING_TIP_8": "You can temporarily mute a server or channel by right-clicking it.",
  "LOADING_TIP_9": "Click your avatar in the lower-left corner to set a custom status.",
  "LOADING_TIP_10": "Group DMs can have up to ten members.",
  "LOADING_TIP_11": "Click the compass in your server list to find new servers.",
  "LOADING_TIP_12": "Drag and drop servers on top of each other to create server folders.",
  "LOADING_TIP_13": "Type /tenor or /giphy + anything to find a GIF for that topic!",
  "LOADING_TIP_14": "Share what you're playing by using the Game Activity settings.",
  "LOADING_TIP_15": "Highlight text in your chat bar to bold, use italics, and more.",
  "LOADING_TIP_16": "Hide muted channels in a server by right clicking the server name.",
  "LOADING_TIP_17": "Customize Discord's appearance in the user settings menu.",
  "LOADING_TIP_18": "Link your favorite social media accounts in the connections settings.",
  "LOADING_TIP_19": "You can create channel categories to group and organize your channels.",
  "LOADING_TIP_20": "You can join up to 100 servers.",
  "LOADING_TIP_21": "You can drag and drop files onto Discord to upload them.",
  "LOADING_TIP_22": "Change each participant's volume by right-clicking them in a call.",
  "LOADING_TIP_23": "Right click to pin messages in a channel or DM to save them for later.",
  "LOADING_TIP_24": "Type a plus sign before an emoji name to turn it into a reaction.",
  "LOADING_TIP_25": "You can type /nick to quickly change your nickname in a server."
}