'm not sure I even agree with what you're saying. The me of 10 years ago learned by trial and error that if i launched my upper body downhill before a turn, I could more or less survive in moguls and steeps.
You don't have to agree, just go experiment. The fact remains one can't release if still uphill. Most people's issues with sideslipping are related to that. They try to do it while leaning uphill.
We don't just get this and are good forever on all slopes. There's always a pitch where you'll have to be conscious of it. Or a condition, such as round line in moguls.
Your previous "launching your body downhill" probably enabled you to ski stuff others wouldn't. It also required a good amount of guts. It served you well in many respects. Just because you did something to the extreme doesn't invalidate the appropriate level of it. Sounds like you've already ingrained moving into the new turn, which is good. Play around with the feet thing on flat cat tracks. Just stand there and tip one foot to little toe side- lift the arch. See what happens if you allow yourself to tilt towards the tipped foot.
Flat spins on snow are good for your release moves. I assume you're very good at sideslipping? If not, get good at it.
Do the skiing into neutral awareness. Notice where your neutral spot is. Is it just before you start the new turn? Too late. Ideally it should be in the middle. You can do it anywhere, even in gentle terrain skiing slow with kids. Makes it interesting.
Go from standing across the hill facing skier’s left with the skis edged to flattening the skis, standing up, allowing the ski tips to find the fall line and then edging the skis into a single right turn.
Your standing up likely supplies a rotary force that turns the tips downhill. You can do it without standing up - just turn the tips downhill. Now with that it's likely we do a subtle body rotating move also. It doesn't take much.
Go try this experiment on a groomed surface good for sideslipping. Sideslip with your weight way forward and way back. But do it while not twisted-facing downhill. So you're playing with just fore/aft. Common thinking is forward brings the tips down, back the tails. Or even vice versa. See what happens.