No, not in discrete, native independent audio channels. It could be simulated by techniques that are more capable and amazing as time goes on... the audio equivalent of deep fake videos.
As you know, historic, standard analog FM Stereo is a two-channel system. Mono (L+R) and difference (L-R). The present matrix sorts it out to Left and Right. Because L+R remains in its original place, FM stereo is compatible with mono radios.
Compatibility with existing consumer receivers was the goal. Same with color TV, your black and white TV still worked. As the world changes the need for long term compatibility may fade.
mpxbroadcast- if you experimented with adding Dolby or other encoders to a FM stereo broadcast system and got good results, this means you are interested in audio processing. You must be asking this because you like sound, correct? Do you seriously believe the radio industry needs surround sound to help reach an audience? Radio is already neck deep in processing now. Have fun, and perhaps something you do will capture the attention of folks in a way they enjoy.