What is Minecraft Preview?
Best answer: Minecraft Preview separates the long-running beta program from Minecraft: Bedrock Edition into its own separate game, allowing Minecraft players everywhere to experience the latest features, changes, and fixes coming to Minecraft in the future. Minecraft Preview will also eventually come to more platforms than the aging beta program and open the doors to even more players.
Breaking down Minecraft Preview
Minecraft didn't become one of the greatest and most successful games of all time with Mojang Studios resting on its laurels. Minecraft's creators constantly bring brand-new content and updates to the perpetually evolving game and ensure the community is involved every step of the way through the release of experimental pre-release betas and snapshots.
Minecraft Preview is the next chapter of this effort and aims to make it even easier for interested Minecraft players to test upcoming updates and changes, submit feedback and suggestions, and help contribute to the continual growth of Minecraft. Essentially, Minecraft Preview is a separate game that players can install on supported devices, and serves all the same purposes as the existing Minecraft: Bedrock Edition beta program but with fewer restrictions and compromises.
The old Minecraft: Bedrock Edition beta program was available on Xbox consoles, Windows PCs, and Android devices, and was an optional program that goes through the full Minecraft game on those platforms. Because of how the Minecraft: Bedrock Edition beta works, it was limited to the platform on which it already exists and forced players to choose between playing the public version of Minecraft, testing pre-release builds, or constantly switching between them by unenrolling from the beta program.