It should be noted that Mysterio is scheduled to appear at the Motor City Comic Con in Detroit, MI on the Saturday and Sunday of MITB weekend. Tickets are $50 for autographs and $60 for photo-ops. (H/T to @Wrestlevotes.)
Unless WWE pulls Mysterio from the signing at the last minute, he will not be in the match at the pay-per-view.
WWE will officially announce the RAW participants for the men's and the women's MITB matches on tonight's RAW during a special MITB edition of "A Moment of Bliss" with Alexa Bliss.
The 2019 WWE Money In the Bank pay-per-view takes place on May 19 from the XL Center in Hartford, CT.