Hi Vlad, Sadly the days of pre-release free demos are mostly long gone
As mentioned, you can cancel a pre-order if you wish.
Personally, i am a tad disappointed by Bethesdas marketing ploy of announcing a BETA that is really just a stress test, and a limited one at that. But i will still be buying the game having seen decent footage now, as i love the fallout universe and have wanted to roam with friends ever since playing Fallout 3.
The game may not be as wholesome and fullsome as Fallout 4, but then it I’s not supposed to be Fallout 5 either (so far as we are aware anyhow lol)
Oh, and i remember playing games when, nevermind having just a few pics in a magazine to go on, you had to type in several hundred or even thousand lines of Basic or MachineCode to even play the game as free audiotape copies were too expensive to give away :-D