From the series summary:
Depending on how you read that sentence, it could mean two potential options:
1. The main character likes feminine things but was unable to enjoy them in his old world due to the standards society puts on men, and now as Miranda she can enjoy them thoroughly
2. The main character legit felt trans but was unable to come out due to society, so when he died he was all “oh nooooo I got reborn as a girl I can’t believe it I certainly never wanted this to happen but since it happened, I might as well wear a variety of cute dresses, not that I want to or anything”
Either way, yeah it is somewhat of a fantasy. But we get tons of manga here like “the middle-aged man who was deserted by his old company adventuring party turned out to have extraordinary powers and gains a daughter figure” or “I came to another world where I was a loner virgin, but now that I brought Japanese cuisine to this new world women are begging to suck my dick”. So honestly, why shouldn’t we get a series about a guy who just wants a slow, peaceful life as an aristocratic maiden?