Hello there @bartoszpie!
The information available on the subject comes from the latest migration article. There is no fixed date for the move yet, but it’s bound to happen in one of the updates for UE5.
Deprecations
Audio Volumes, Sound Class Mix, and Sound Cues will be deprecated by UE 5.0, with plans to remove them in a future release of UE5.
- Sound Cues will be superseded by MetaSounds, which will be available in UE 5.0.
- Sound Class Mix will be superseded by the Modulation and Submix systems, which are now available.
- Audio Volumes will be superseded by a new system currently in development, which will be available in UE 5.0.
Users are encouraged to move to the new versions of these systems as soon as possible.
As for the problems with attenuation, I found a related bug fix report that was tackled and resolved for 5.6, updating to that version could resolve your issue:
Still, I would prioritize moving your pipeline to MetaSounds, whenever possible.