Question about Creative Sound Blaster PLAY! 4

Hi, This is probably a mistake in the specification here.

This refers to the support of an analogue headset with a 3.5mm plug according to the CTIA standard (as encountered in small to medium-sized headphones). Just a few years ago, all mobile devices accepted a headset or headphones in this way. Now the industry prefers to sell wireless, expensive headphones as an add-on.
An example of such a wired headphone would be the SHURE AONIC 215. Pretty much every wired headset with an analogue connection also has this type of plug (e.g. Jabra Evolve 30 II Stereo).