If you look at the 2019 Trainee Bid there is someone who called HR and they said that there would be an open bid at the start of 2020 (around January). It's speculation that it is because there were so few trainees last year so it was extremely difficult to recruit, making it necessary to have another bid mid year.
But there is a January bid rumored for the past two years. So honestly, I don't think there will be. But it is possible.