I'm not a fan of correlation is all they can come with up either, but if there's strong correlation for nearly a century (the first studies on cross-sex hormones in adults are quite old) that transition and family/peer support helps reduce depression and suicidality, I'm inclined to at least be supportive.

With children, it's even easier for me in particular to lend my support because the data are still strongly in favour of support even if the kid grows out of it later and blockers are largely reversible with few side effects. But as you say, we need to continue to monitor the literature to see how our understanding of the situation changes as we learn more.