“The RCA rejects conversions done by other Modern Orthodox rabbis and also rejects those done by Chareidi rabbonim, such as the Vaad of Queens (one of their converts was recently deported from Israel).”
The RCA, in compliance to the Rabbanut of Israel, adheres to standards and policies that exclude some MO rabbis. I don’t know about any particular case, like the Vaad of Queens. I don’t even know if they consider themselves charaidi. From what little I can tell from their web site, they are a vaad that is made of the local rabbis, not necessarily charadi.