The only requirement for this list is that the princesses present have not been made, printed in the outfit they are shown in, they may already be out there just not in a certain outfit. I am not considering any pictures on the internet of Mini Dolls alleged to be those of 2019 release dolls legitimate until pictures depicting those same dolls are posted by Lego or major Lego retailers.
Princess Tiana - Princess and the Frog - Wedding Dress
This could be such a good Mini Doll! The dress design could be done using the full skirt as seen in 10762 - Belle's Story Time and the hair piece using the shape and style of the Ice Queen CMF hair piece but in the appropriate green. We don't yet have a Lego Tiana so this would be a first!
Princess Ariel - Blue Sight-Seeing Dress
This dress is my favourite outfit Ariel wears in the first little mermaid movie and is the only one other than her wedding dress that Lego haven't made into a Mini Doll.
Mulan - Matchmaker Dress
The only Mulan figure we have so far is reminiscent of her other dress - I have always liked this pink iteration that she wears when she goes to the match maker just that little bit more.I think for such a powerful Disney Character it would be nice to have variety.
Cinderella - Live Action, House Dress
I have made no secret of the fact that this is my favourite Cinderella movie of all time. I would love to see this version of her dress in mini doll form. It may require a new mold for the hips and legs as the dress is 3/4 length and that is what separates it from the other Cinderella dresses.
Princess Aurora - Blue Dress
So far we have had two Princess Aurora Mini Dolls in the dress above - but in the pink and not in the blue. While the most recent set: 41152 - Sleeping Beauty's Fairytale Castle did include a sticker that alluded to the colour change of the dress that takes place in the movie that went on a post in the set, having a blue version of the dress would be a welcome change.
Pocahontas - Pocahontas
We haven't yet had a Pocahontas Mini Doll in any form. We have had her raccoon in a cute blue print, but no actual Pocahontus. There is an existing Mini Doll skirt mold with a fringed style that has been used in the Elves and Friends series from time to time, that could perfectly illustrate her skirt, while the top can be printed nicely.
Princess Shuri - The Black Panther
Princess Shuri is technically a Disney princess because Marvel films are Disney Films, and as the younger sister of King T'Challa she is second in line. She has, I understand, been made into a mini figure - but not a mini doll - this could better illustrate some of the beautiful design work that went into the princess - played by actress Leticia Wright - and her outfits.