On the config/voice-assistants/expose? page, the columns named "Aliases" is still there, and the current aliases are displayed, but there is no "submit" button to create new aliases.
Just hit enter when you finish typing the new alias, then you can close the pop-up. The alias has been added, but you may need to reload the list page for the column to show it.
What Drew said.
And for the record it's also a horrible UI choice. Not giving user feedback that a commit has occurred... (it took me two or three trips across this particular one before I figured out the save actually happened when yih exit the text box, it should throw the 'ok button' color to primary indicating there is data to save and earn if you exit without hitting it...)