I personally feel that this song was exceptionally unique; it seems to blend several music styles

I agree! The lyrics pass such a good message, principally “C’est pour de bon!”. It gives me vibes of a hopeful future where workers will control their own destiny.

and the only other French socialist songs I can think of off the top of my head are the Internationale and the Worker’s Marsellaise.

“Les noveaux partisans” is also an amazing song! I recommend it, might post it later in case it hasn’t been posted yet.