Could be wrong but this does not sound sound outlandish for a alpha. There should be no point to ruin a name/brand before it is out. You should not leave a "review" of a unfinished product.
If the product is unfinished, why is it being released to the public, in any capacity?
If they want to playtest and find bugs in their unfinished product, they should do that. By paying a QA team and playtesters, not by trying to dupe streamers into generating free advertisement.
You have never played an early alpha of a game and signed a NDA to not disclose it I did this with many games the finals, th division heatland, x defient, arc raiders etc. although in this case since there are yt videos and streams seems a little weird. I was uneducated the games I am talking about when I played had watermarks on them and were made for testing etc had no idea the game was like viewable. In this case it looks more like if tarkov or an EA game said you can't leave reviews.
To clarify yes I fully agree that not ok and didn't know the full facts.