I think the reason so many have a problem with this is because of the way Dina chose to word the sentence. Particularly because as a child psychologist, she should know better. This "asking permission" of a small child, coupled with other statements she has made that indicate an indulgent parenting style, indicate that even with her child psych background, she did not view Max as a child to be parented, but as an "equal" little man, the "elmer's glue" of the relationship, saddled with self-imposed peace making.
I agree with other posters that she seems, from her own statements, to have a weak grasp of what is developmentally appropriate-- EVEN for a child who may have been gifted. Gifted children need even more limits and sophisticated parenting skills than typical children, as they frequently push limits to find out where the boundaries are. The author of the article also ascribed her parenting to a "child wonderland" parenting style. (Which, IMO, is indulgent/ permissive parenting style.) The free access to the fully stocked candy drawer comments are also a window into that kind of parenting. The parent indulges openly and lovingly with "stuff", and the child sets the limits.
If, for example, Dina had told the author, something like, "I wanted to meet the woman who was helping care for my child, and I set up a meeting with Jonah to discuss that. Then I told Max that his Dad and I agreed that it would be good for me to meet Rebecca..." (and included details of when that would occur) that would have been received very differently than the way she chose to word it.
It gives the impression that if Max had said "no, I don't want you to meet her", she would have acquiesced. Or worse yet, set up an acrimonious meeting and relationship, because Max didn't want her to meet RZ, and now she has said she wanted to. These sorts of decisions are WAY above the input of a 5 -6 yo, IMO. It puts too much on the shoulders of a child already in a twice-blended family situation, imo. It is also a hallmark of permissive/ indulgent parenting style (easily googled), which presumes the child is a small adult, and equal in decision making.