So:
Since it does not have the "DUOS" brand suffix (as it does here, for example: https://www.digitec.ch/de/s1/product/samsung-galaxy-s8-duos-620-64gb-dual-sim-12mp-midnight-black-mobiltelefon-6198764), I assume that it does not.
-Yes. Since a while Samsung has released an update, and since then you can deactivate the Bixby button in the S8 and S9.