But I saw that the new After Effects CC 2019 version has an updated Java Script engine ,so 😊 I would be very thankful if someone could say if it is now possible and explain the expression to me.
All additional information can be found in the post in the link.
I get where that previous thread was coming from and in a strict since this effect properly done would be a summation of dx/dy's. But I don't see why we couldn't cheat.
Precomp the flare (you may need to greatly extend the duration of this comp)
Put Timewarp on that comp in your main timeline
Get audio keyframe data. (top menu bar) Animation -> Keyframe assistant -> convert audio to keyframes. Take a look at these values to get a range of what its going to be spitting at you.
For the speed value inside of timewarp. ease(\\link to audio keyframes\\,\\~smallest value from keyframes\\,\\~highest value from keyframes\\,\\minimum speed you want the flare to move\\,\\maximum speed you want the flare to move\\)
You will have to fill in all 5 values inside of the ease expression. Its important to remember that timewarp takes speed from % so a value of 50 is 50% and this speed is relative to how fast the flare is animated in the precomp.