I bet my money thats where the inspiration or part of it came from, especially if they grew up with the show(its quite popular in japan) and fondness over the main couple
Have you ever read official manga from your favorite doujinshi fanartist who turned professional. Sometimes alot of those ships or characters elements they came used back then tend to linger into their official published work, its kinda sweet in a way, like a fandom imprint never leaves you even after you leave.
True they may have done a few Conan djs in the past
He kinda looks like Shinichi/Conan but taller, he has the same big glasses