If you open pre-3.3-adjusted photo that had Highlights & Shadows applied to it, then you will see the old adjustment tool, with a new “Upgrade” button in place. Turns out you can save that old adjustment as a preset (set to zero even), and then add that to any new photo.
In most cases, I found the old Shadows tool to be overly sensitive. However, this lets you get back the Radius, Color Correction, and High/Low Tonal Width adjustments. Mid Contrast, which I found to be the most useful of the Advanced adjustments, has been promoted to the top level in 3.3.