Yeah, I read that. Kind of vague, isn't it.
Lots of people are "big supporters of 0".
A “true mother” and the extended family would have a "true name".
If David doesn't want to share his opinion, or knowledge, of who this person is then all he has to do is say so.
A simple "I'd rather not say at this time" would suffice.
...But his true mother and her extended family in the US are at this point, a significant part of the effort that has made him a political figure. These people are being concealed for a reason...
And you are asking that he place their names here? Are we adults here or children playing games?