Not very true. If you want to increase your average speed, the easiest way is to minimise the time you spend between flat-out and your autopause threshold. There are limits to how high you can set your autopause to before the competition sites complain, so the safer approach is to charge up to every junction, emergency stop at the latest possible moment, then sprint back up to full speed as soon as you can - which will be fine until you misjudge "the latest possible moment"
and then it will hurt. Lots. And yet, I still see people cycling like that. I expected it to die off (hopefully not literally) once Strava wasn't new, but there seem to be more Straviots every year. It's nice there are more people cycling but crikey!