Well I've shared Juneteenth on the Shrek Wiki of his original tale on a forum, but I thought I'd say if it wasn't just showing the popular characters or the villains who wish to express freedom with songs. Well if Shrek had a story of celebrating Juneteenth in his own world it could sure include flags of the characters who had several hero scenes like Big Bad Wolf, Donkey, Shrek, Fiona, Gretched who is one of the ogre resistance members, Gingy, Dragon, Puss In The Boots and any other character who repeatedly had some rescue scenes in the Shrek films. An animated film of this holiday about freedom could also have flowers that symbolize freedom for sure. If this freedom holiday Juneteenth was celebrated in Shrek's world it could sure let Dragon herself be the symbol used like the star of Texas is used in real life, because she's a dragon who helped several masters at different times.
Valentines Day is shared as much as people's favorite national holidays, but this freedom holiday isn't known by everybody yet, and I agree Kindness and Freedom are important enough to let Juneteenth become Federal. That's why I shared additional ideas of celebration here besides letting characters sing about freedom.