Virtually everyone who has "Flex to Release" as their mantra equates "extension" with a pushoff. Either a downhill check and then an up extension pushoff, or a rotary extension pushoff from the uphill leg. Or even both in the same turn. Arguing that this is not necessarily the case is like arguing religions usually. You'll get nowhere.
"Flex to Release" is not some magic bullet.
Here's a classic problem with "Flex to Release".
Intermediate skiers on steepish terrain - say that trail skier's left of the West wall at A-basin, no bumps. Pitch is great enough to be of considerable concern to many in the group. What happens?
Skier is traversing shopping for a turn. Tries lightening the downhill leg. Nothing happens. The downhill leg begins to shake and wobble as a sequence of flexing then weighting occurs since nothing is happening when they flex.
At some point, the skier must turn because they are out of space. In order to make it happen now, they push the uphill leg out to initiate the turn and head downhill. Yes, this is not how they are supposed to do it, but it worked at least.
Why didn't the "Flex to Release" work there?
The skier is afraid to go downhill. Because of that fear, they have their body oriented uphill and thus their weight is over the uphill ski. Flexing the downhill leg does nothing except make them balance completely on one foot. This makes them more fearful. Since their weight is uphill, there is no "toppling" downhill as they flex the downhill leg. To topple downhill one must have enough weight on the downhill ski that flexing it causes an imbalance and the body goes downhill.
One can topple downhill releasing both edges also by simply moving the body downhill. As the body goes down, at some point the edges will release and the tips will go downhill. Don't even need to flex or actively tip to make the release. Since the body is connected to the boots, as the body moves downhill, the boots tip downhill and release the edges. That's the basis of the so called "do nothing" turn.
Btw, a wedge turn is a steered turn at low speed. The release movement is very small.