If he makes it clear that they are withholding financial support given to prior candidates, then people will donate to him directly, and the DNC will be publicly called out for favoring past candidates. That’s the last thing they need after the Debbie Wasserman-Shultz/Hillary Clinton scandal.
I really don't think they care. These people have no shame. I read that 40% of the leading Democrats that endorsed Cuomo had previously called for his resignation after his numerous sexual assaults came to light. The party that lauds itself as the champion of and defender of women's and minority rights rallied hard to support a corrupt sexual predator over a Muslim, simply because he was progressive instead of a conservative. Hell, arch sex pest Bill Clinton endorsed Cuomo.
These people have no shame. "Calling people out" or "slamming" people means nothing. If calling people out changed their behavior, Cuomo, who sexually assaulted at least a dozen women, would have never been seen in public again.
Seriously. How can you think that leaders that openly endorse a sexual molester give a single fuck about being called out publicly for their bad behavior?