The single biggest indication that a child will continue to transition is social transition.
Also, on this, social transition is often described as harmless, and anyone in opposition to it is painted as unreasonable.
But we know that children find it difficult when a sibling is born and they aren't the only child or the youngest anymore. We know children find it difficult when their parents split up. When a step-parent comes along. When they move house. When they move schools.
Yet somehow becoming a son and brother instead of a daughter and sister is not going to have any negative effect. Referring to the old self as a "dead name" and pretending to be a new person is not going to have any negative effect. Re-introducing oneself to everyone as a new person, new name, new pronouns - that's all fine too. Plus the stress of worrying whether people will comply, whether people will remember, whether people will take it all seriously - none of that is going to have a negative psychological effect? It sounds incredibly stressful to me.
No child wants to look stupid. Children like to be taken seriously and not be laughed at. So the pressure to persevere once a social transition has been made public is huge.
Why is there pressure on children to make their new-found identities permanent? Why is there pressure on children to come out as gay even? Who the hell needs to know who an eleven year old fancies in theory or how they feel about their sexed body?
I've said it before - women who are happily getting married to a man they love often find it disconcerting having to change their surname (obviously not mandatory to do so but most do) and those are grown adults entering into a marriage voluntarily, making an expected and socially acceptable change. But somehow changing your name, your position in the family, and reinventing your history causes no issues?
People who emigrate voluntarily have issues around feeling like they belong elsewhere but have lost touch with their country of birth. People with parents from different countries or races sometimes struggle to find that sense of belonging also. It's normal to want to fit in, it's normal to want to be able to rely on some facts remaining unchangeable. Hell even East Germans felt weird at becoming just Germans after reunification, and felt their shared history growing up in the DDR was whitewashed over, hence a healthy market for DDR nostalgia continuing to exist.
I'm sure in a few years we will see detransitioners who feel that their parents contributed to their lack of sense of self by readily ditching their existing identity and playing along with a new one/several new ones. How can you feel unconditionally accepted by your mother as Olivia Jackson when she also accepted you as Kai and as Alex? Do we really think children aren't attached to their name and their place in the world, and that they are resilient enough to reinvent themselves without any issues? When adults aren't?