Yes sounds good to me.
Don’t you have a warning saying that it can’t find the file ?
Maybe it’ll help, I override both action_default_ask_rephrase and action_default_ask_affirmation with the code I found here : rasa-demo/actions.py at 096568e64df4c25902f91fcf7b409fa2fcd05b16 · RasaHQ/rasa-demo · GitHub and here rasa_core/action.py at 431d4c89c5025bec2be51c065add2ab272089bdf · RasaHQ/rasa_core · GitHub .
Add some logs to see if the csv is correctly read. Don’t forget to add both of them in your domain.yml so that they are called instead of the default one