You would just have to make clear that you already have the missing chapters written. If you submit a story you haven’t updated in months, it doesn’t look great, but if you add in the notes that you’ve written the rest of it and it’s just sitting back it works.
Showing you have a consistent update schedule is about us partnering with you. If you have other completed stories, you show you can finish books and go to the end. But if you’ve never finished anything and the only thing you have hasn’t been updated for months, not a favourable picture you paint of yourself. It would be better to start posting again and being consistent before applying.
If you don’t meet the criteria today, that doesn’t mean you can’t just meet them tomorrow