Recent reports suggest the Samsung Experience 9.0 user interface expected to run on the Galaxy S9 will include updates to its emoji designs, which will make them more in step with other platforms, such as stock Android and iOS.
Looking at Samsung's patterns, where the Galaxy S8 ran Samsung Experience 8.o and the Galaxy Note 8 ran Samsung Experience 8.5, it is likely the upcoming Galaxy Note 9 will run an interface called Samsung Experience 9.5.
The Galaxy Note 9 will likely have its own custom firmware features, especially some pertaining to its S-Pen stylus; however, the interface will likely include similar updates to the Galaxy S9 firmware, such as updated emoji.