Yes, it still works this way.
Please note that the following are output-only (only sent to the display, never back to your RPG program):
These fields determine what the user sees (choices) and what the corresponding values are to be sent back (choices values). You should bind a comma-separated list of things to be sent the display, here.
For sending stuff back to your RPG, that will be done with the "value" property. So I could say the following property is both input/output:
Your program can set this to a comma separated list of things that should be marked as "selected". When data is returned to your RPG program, it will contain what is selected (including any changes the user has made.)
You must also have the "multiple" property set to "true".