Samsung really wants you to use Bixby. That's why he included a physical button to access his terribly malnourished assistant on most phones since the Galaxy S8. Samsung has always tried to prevent remapping this button, but the Galaxy S10 has changed that. The official Bixby remapping feature of this phone is spreading to other Samsung devices.
Until now, the owners of the Galaxy S9 and Galaxy S8 have seen the new Bixby feature appear on their phones. It arrives via a Bixby update. So, if you postpone them because you do not care about Bixby, now is the time to worry about it.
Once you have the latest update, the settings include an option to attach Bixby to a single or double-click button. The one you have not set for Bixby can launch another application of your choice. So you can push Bixby on a double tap and never use it while adding something useful at the touch of it. This feature is part of Android Pie. Therefore, do not get upset if your phone is still waiting for OTA.