There is an option to require players to download and use the Resource Packs applied to a world. Set by the Host in the Resource Pack world settings.

The way it is currently working: Players are prompted to download the Resource Packs when joining, but on exit because of user leaving, game crash, or other, the information that was downloaded is lost. This requires the player to download it again, despite doing it recently.

The way it is supposed to work: Players download the Resource Packs when joining, and it is retained upon leaving the world, and prompted to download only when the pack is updated. 

Additional Personal experience: It appears the Resource Packs are downloaded directly from the Host, bogging down my internet and kicking me from Xbox Party. The download is small, around 40MB, but takes around 10 minutes. While this is happening, any players in the world will experience high amounts of lag and desync. I wish since the pack I use is Official, it downloaded from the Marketplace instead of my weak internet. Legacy Console Editions had a solution of Trial Textures, which were free and did not use my connection to send them.