I can confirm this, although my pilsener was quite good after a few months. It went from great to bad and from there back to good.Drink among the last bottle No Boil beer standing for just over a month in the fridge. It looks a bit cleaner, tastes the same as before, but got some bad smell.
Making few batches of No Boil Beer I have found that this is the greatest disadvantage of this method. It's not stable and it's fast changing to worse.
As far as I can tell, it's best to drink it within 20 days. The flavor and the taste change afterwards.