It was leaked a little early on Steam, but Capcom has now officially announced E. Honda, Lucia and Poison will be making their way to Street Fighter 5 on 4th August.
On the final day of Evo 2019 (and the day of the Street Fighter 5 grand finals), the characters will be made available to buy individually, then the following day a "Summer 2019 Character Bundle" will be released - including different battle costumes for each fighter.
It's likely this was meant to be a big announcement set to go live during Evo, but the leak seems to have forced Capcom's hand to go ahead with the early reveal.