All based around one gimmick? Check.
Limited lifespan? Check.
Reliant on constant maintenance? Check.
If that video is to be believed, only available to a very limited audience (Those able to play at the time of the stream)? Check
If its a genuinely good game, they are crippling themselves with the method of releasing it. If its a bad game, they are trying to sell it purely on the gimmick, the latter option makes infinitely more sense to me.
I give it 6 months. Tops. And then it will either release an "Infinite mode" for the game, or vanish completely, to the same pit of obscurity and stupidity the Flock is in.
Also I reckon you will get a LOT of boring streams of overcautious players hanging back and stalling rather than being fun to watch. Good viewing material should involve players taking risks. That will rarely happen in a perma-death game.
Its possible I am wrong, if so then congratulations to the dev team! But I am highly skeptical, and certainly have no interest in playing/watching it myself.