Not quite. It seems like creators have until September 28 to choose to publish existing community contributions, and if they don't, it seems like they will all disappear. That's how I interpret, "You have until September 28, 2020 to publish your community contributions before they’re removed."
If you have contributions currently saved as drafts, these will be available for the next 60 days (until Sept 28 2020), and you have until then to publish them before they’re removed. Any already published contributions (titles, descriptions, captions, etc) will continue to show up on videos and can be managed by Creators in YouTube Studio.
IIRC this was basically what they said when annotations become unavailable to new videos. They're completely gone now, so probably a year or so until community contributions are completely wiped.
I've done some translating on YouTube. What it means is if your translation is in draft mode (you're still working on it) on 9/28 it will disappear. The video creator shouldn't need to do anything here.