Just got the Bixby button remap via galaxy store
https://www.sammobile.com/2019/02/28/samsung-bixby-key-remapping-older-flagships/
Remap Bixby key on older flagships
Once the update is installed from the Galaxy Store, just go to
Advanced features in the Settings app followed by
Bixby key. You will be presented with two options. You can either set a third-party app to launch with a single or double press of the key.
The caveat here is that you can only select one option. So either a single or double press can be remapped, not both. The option you don’t select will continue to launch Bixby Home. A long press will always bring up Bixby Voice.
This compromise means that users don’t just
disable the Bixby key entirely and never open Bixby Home. By allowing them to remap a key press, Samsung is ensuring that Bixby Home doesn’t get shut out by users for good.
You can try this out for yourself on the Galaxy Note 9, Note 8, Galaxy S9 and the Galaxy S8 series. We have and the feature works as expected.