i guess many of them are real. i remember how there were always threads on kraut as well as on kohl, just galleries of kindergarden age kids in swimwear and then fat old incels drooling over them.
but considering the evil reality of the weaponized internet (that has become a mechanism for powerful elites with infinite money to selfishly force behavior on poor people, thus circumventing democracy) you can never be sure that the interest in children is actual incels because it might just be algorithmically created. it might just be one weapon in the arsenal of modern cyber armies in order to lower the quality of a place and destroy it by flooding it with content that makes any decent user leave the site. don't forget how they behaved during covid.