My guess is that Shapiro said No.
My guess is that the POC/LGBTQ committee, that's been chaired by Barack Obama & running Biden/Harris like a pair of Muppets for 3-1/2 years, vetoed Shapiro because they're that far to the left. He's too friendly with Israel.
If Josh Shapiro had been an "I hate Israel, I love the Palestinians" Jew like Mayorkas (yes, he's a Cuban Jew), Yellen & so many others on the lunatic left-wing fringe, it would have been Lust At First Sight.
Why go through this public self humiliation ritual if you didn't want the job?