Well almost, angle between the horizon and the longitudinal axis, not the chord line.
Those are two unrelated things, you can fly a certain glide path with a certain AOA. And this is in fact exactly what is done in real life. You can fly a X degree glide path with angle of attack Y. Thats the tricky part, matching the glide path with correct AOA. The same way you try to match approach speed with glide path on a “normal” aircraft.
The problem in general / commercial aviation is that most aircraft don’t have an AOA indicator, thats why we fly a certain approach speed depending on the gross weight. What you are basically trying to achieve is flying the approach with a constant AOA (without AOA indicator) no matter the aircraft weight. During level flight you can directly relate speed to AOA for a given weight and configuration.
In other words, its not all that different if you think about it. The difference being that the F/A-18 has a AOA indicator, most other aircraft do have a AOA probe but the AOA is not displayed in the cockpit, instead AOA is only used for stall warning activation and low speed cues. AOA is translated into speed, the F/A-18 uses AOA directly.
One way of looking at it: the Powered Approach mode is like flying a conventional aircraft on autopilot in FLC / IAS mode with approach speed set while using thrust / power to control descent path.
I think @Raynen can best judge if my take on it is correct.