There are shades of explicit not necessarily amounting to stereotypes (although, in presenting us with an elderly chap whose one experience of - unrequited? - same-sex attraction in his youth tragically blighted his love life forevar!1, I'd argue that she is giving us stereotypes, 1960s ones).

Given the extent to which growing up gay can be an isolated, miserable experience, it'd have been nice if one or more of Potter's peers had been other than heterosexual. 'Twould have been interesting to see how those in the wizarding world accommodate/react to queerness.