You may have heard about Bixby, Samsung's new device assistant feature that won't even have voice commands in the US at launch. Well, if you were planning to remap the Bixby button to something more... useful, prepare for disappointment. Samsung has reportedly blocked that modification in an OTA update.
The Galaxy S8 has a button on the left side of the phone to activate Bixby, which is a waste of space if you don't intend to use Samsung's assistant. Developers figured out ahead of the phone's release that the accessibility service could be used to intercept the KeyEvent triggered by the button. That meant it could be remapped to something else, like Google Assistant. It seems Samsung was not too happy about that, and has blocked it in a new OTA.
This news comes from XDA dev Flar2, who was updating his Button Mapper app for the GS8. He notes that his new Telus Galaxy S8 allowed remapping of the Bixby button with Button Mapper when he received it, but an OTA update changed the button's functionality. Now, the Bixby button's action is no longer routed through accessibility. Thus, it can't be changed without root access. I'd expect a similar OTA to hit all the other carrier variants as well.