Same here. I've kind of dreaded this day and thought why is there no standardized 'playlist protocol' or playlist format that music services could share. This is like the 4th time I've had an old music service shut down and lost all my playlists with no migration path.
The problem may be that the m3u would contains artist name, song title, and position in the playlist, and even if you could export this, it would not be very robust to import somewhere else.
