That's all phones ever, not current/popular models. When you restrict it to the last 10 years, you get about 12%, and of the 70 most popular models almost a quarter are equipped with a barometer.
That seems unlikely in an environment with no cellular / wifi signal. Theoretically possible, but expensive for battery and probably disallowed by the OS.
146/1109
now correct it for number of sold phones each (estimated by looking at the 70 most popular models) and we'll get why they said 1/4.