We've implemented and enabled a bandwidth saving feature, which was introduced in a recent Minecraft update. This feature caches (parts of) Minecraft worlds on your client, without the need to download the same parts over and over again. This will speed up your Hub and Game Lobby experience significantly, and keep your bandwidth usage low. 

We've also enabled this for certain games, such as Hide and Seek and DeathRun: once you've played a map once, the second time, it'll load without needing a download.

We're currently testing all this on our Asia Region - we plan to release it worldwide this week.