"recent stuff" is somewhat relative. the loudness war has been fought on other fronts than just CDs/mp3s. my cassette player from the 80s had a loudness button. the sales rep at Guitar Center bragged about the easiest one-button sale for a 1RU piece of gear to add to your rack that made your sound better. it was just a loudness on/off button. so it was playback device dependent at that time which allowed the listener to choose it. they just moved the battle field to format itself and took away the choice
The "loudness" button on old equipment is actually a combined bass and treble boost, designed to the make the music sound louder at low listening levels by compensating for the effects of the equal loudness contour. It's a great idea for anybody who cares about protecting their hearing. You can do even better using modern DSP by equalizing to a curve based on the difference between the equal loudness contour at your preferred listening level and the equal loudness contour several decibels louder.