If they were relying on this study to claim that gender affirming surgery is harmful then the answer is yes, they are wrong and don't understand what the study is and is not able to say about the issue.
Speaking of issues, you seem to be conflating them. Children receiving care which is different from adults receiving surgery - they are not the same.
Another issue you have is that this study really only shows what we already know: people who are transgender and nonbinary have a much higher rate of mental health problems like suicide. They also have a higher rate of trauma and PTSD as a result of trauma.
But some European countries are calling for and doing more research on the issue. None are actually stopping gender affirming care and saying that it is harmful, which is what you imply. (I don't really count Russia as European in any meaningful way culturally)
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Kellan Baker is spot on about the intentional misinterpretation for ideological and political reasons that is occurring.
There's even a pseudo-science industry in place to offer "scientific" evidence for anti-trans laws in court.
Three major waves of opposition to transgender health care in the past century have cited faulty science to justify hostility
www.scientificamerican.com
openyls.law.yale.edu
Throughout the last five years, a major question has been: “How did the anti-transgender pseudoscience movement achieve success so quickly?” In responding to this question, it is important to first note that cisnormativity is nothing new. Anti-transgender sentiment has been vocalized louder and...
www.splcenter.org
How a political movement manufactured scientific misinformation and legitimized hate.
www.openmindmag.org