I'm sure you're aware of this, or at least experimented with it, but my reference above to choosing "selected" or "playing" is indeed synchronized between all relevant panels. I recognize that you're looking for an option to enable syncing those two modes, but it is already synced. Perhaps that's why the now-missing option was removed.
I have these panels showing: Track Details, Lyrics, Artwork, and Bio. All have a button that says either "Selected" or "Playing." Changing one changes them all.
Or am I misunderstanding what you're trying to accomplish with an option in Preferences?