They don't necessarily say it is a SOLELY LGBTQ+ allegory (although the creator has said that they liked defying our understanding of gender and sexuality, but whatever). The purpose of the article is that it is relatable to people who are LGBTQ+. And it is. It doesn't matter the intention. What Ranma goes through, and how people interact with him even if done in comedic ways, is very similar to how people who are genderfluid experience life.
Also, you clearly haven't watched enough of Ranma 1/2 or rad its manga. They literally have a character that is a femboy who enjoys wearing girl's clothes. Are you serious? You all will take any moment to try to discredit the LGBTQ+ because of your own prejudices.
