An update to Team Fortress 2 has been released. The update will be applied automatically when you restart Team Fortress 2. The major changes include:

Matchmaking

• Players can now form rematches at the end of a Casual match
  • At the end of a Casual match, players will have 30 seconds to opt-in to a rematch
    
  • If at least 6 players from BLU and 6 players from RED have chosen to rematch, then a rematch will begin
    
  • A rematch will use the same teams, map and server
• Players can now re-queue into Casual Matchmaking during the end of a match
  • Players who decline a rematch or simply don't vote in the rematch voting period will automatically be re-queued
• Updated the way XP is earned in Casual matches
  • Players will now be awarded more XP based on their team's performance at the end of a match
    
  • XP is no longer lost for leaving a Casual match early
    
  • A breakdown of XP sources is now shown when your XP bar fills up
• Casual matches now more strongly prefer to distribute players to teams based on experience, in order to better avoid creating one-sided matches
  
• Casual matches are now more likely to start with fewer than 24 players in lower population game-modes or regions, wherein the wait time for a full match would become excessive
  • The current minimum allowable match size in such situations is twelve players
    
  • The matchmaker will still attempt to place late-joiners into these matches as they become available
• Competitive matches no longer terminate when any player abandons the match
  • Bots will now fill in for players who have abandoned, or temporarily disconnected from, Competitive matches
    
  • Matches that finish at an advantage or disadvantage (e.g. 6v5 or 5v6, not counting any bots) will now result in larger or smaller skill rating adjustments for disadvantaged wins or disadvantaged losses, respectively
    
  • Competitive matches that lose more than one player per team will keep the current behavior of ending the match
    
  • Players who abandon Competitive matches still receive a large skill rating penalty and Competitive matchmaking cooldown, regardless of whether a bot was allowed to take their place
• Greatly improved the reliability of client ping estimates when placing users into matchmaking servers
  • The game client now periodically checks in with the matchmaking server network to estimate ping to each region, and feeds the information back to the matchmaking system
    
  • This should greatly reduce cases of players being placed in regions to which they have poor ping, even when said regions are geographically nearby
• The scoreboard now shows the connection status for missing and connecting players
  

• Added tournament medals for ozfortress Season 16 and Season 17
  
• Fixed an exploit related to the Eureka Effect and carrying buildings
  
• Fixed Live Streams menu not displaying the list of streams
  
• Fixed the flamethrower not drawing the Halloween Spell: Spectral Flame effect during Halloween and Full Moon events
  
• Updated the localization files