In my opinion, this season was the last canonically tbh.  Twilight's appearances in episodes continues its downward trend after a slight and brief uptick in S3.  I decided to make a very autistic spreadsheet with some charts to illustrate this depressing point: https://docs.google.com/spreadsheets/d/16-rolJz2TNsnuMLvKNY9OUy9tn25qD6h6iU2NDTIDHQ/edit?usp=sharing

MP3: https://media.pone.tube/twivoice/s4.mp3
OGG: https://media.pone.tube/twivoice/s4.ogg
WAV and FLAC: upon request (leave a comment if you want it)

Season 1: https://pony.tube/videos/watch/46a53b61-91d2-4c62-a922-9a7eae0b99b6
Season 2: https://pony.tube/videos/watch/12be7a34-ce74-44b3-a9e7-21b401aaad5e
Season 3: https://pony.tube/videos/watch/a3c8a74f-3f76-4b51-8dcf-88dc3cfdea99
EQG 1: https://pony.tube/videos/watch/9c0bc577-18f6-4292-a414-017c450acf4a
Movie: https://pony.tube/videos/watch/9702e2a4-345b-4191-bf16-2c564d5c7ab7