Are pancake primes extinct ?

I think there is another factor at play, too. At least from Olympus and Panasonic the trend is towards lenses with "internal focus" for fast and silent focusing. Both the 20/1.7 and 17/2.8 are fairly slow to focus compared to newer lenses, and I imagine it is relatively difficult/costly to make a new pancake with the focus speed that Olympus and Panasonic wants.

But don't forget, we have seen the introduction of one new pancake lensthing: The Olympus 15 mm/8.