So, for what ever reason if u download minecraft bedrock edition from official minecraft launcher u weren't able to get minecraft preview considering that is a snapshot version thing for minecraft bedrock. I don't know it is a bug or not or is just only happening to me, tough considering that minecraft beta is going away then why can't you get minecraft preview and honestly is just a scam at that point because is like buying a laptop for free but u have to pay for the charger.
Is just made me so so upsset because when it was first notice a pop up on minecraft launcher i was just exited to get a both minecraft edition (java and bedrock). But, when it finally arrive on June 7th i was very disappointed because how is that a full game (bedrock edition) i can't even access a the testing version aka minecraft preview.
Now i made a minecraft bug report on minecraft bugs tracker website and if anyone had the same thing happen to me (u weren't able to get minecraft preview from the microsoft store) go to the link then vote the bugs tracker (if u don't have an account just create one is very simple and quick to make), that way 1 of the minecraft dev team will notice and maybey try to fix it if is possible.