If you’ve seen more “authoritative” sources surely you shouldn’t have any trouble sharing and directing us to these “authoritative” sources. Any why you’re (temporary) mea culpa if you’ve seen authoritative sources otherwise? A person is presumed innocent.
The Gedolim, as a rule, work behind the scenes. You can be assured there are many Gedolim involved, in addition to the ones listed in the aforementioned article.
The money is coming from Achenu Bnei Yisroel, who are elated to participate in the mitzvah rabba of pidyun shvuyim.