I'll concede that its less "give up your voice and everything about yourself for a boy" and more "give up your voice and everything about yourself for this way of life that you are clearly irrationally obsessed over and don't understand at all". But its also made clear via the voice subplot that her mad dash to separate herself from who she was to begin with is itself a source of conflict. Certainly, don't ignore the voice in your head that says "this isn't the place for you", but also accept that the change needs to happen slower than you want, for a variety of good reasons.

I suppose there's an interpretation of Disney's The Little Mermaid where its an allegory for LGBTQ (especially trans) kids. But even then, it mixes its metaphors by adding in the romantic subplot. Luca does a much MUCH better job of balancing the two worlds, because the happy ending is "gets to be human" and not "gets to be human, so they can get married to the person they met a 4 days ago". The Little Mermaid really muddies the water (pardon the pun) by adhering to that aspect of the old story.

And while I have considerable misgivings about introducing the happily-ever-after romantic ending to 5 year olds, Disney does manage to get it more correct: Beauty and the Beast shows the (potentially problematic) relationship between Belle and the Beast developing over time, as they get to know each other. Tangled has the love story as ancillary to the main story of getting out from under the thumb of an abusive parental figure. Even Sleeping Beauty expends a lot of screentime to show how the love story specifically contradicts the arranged marriage to be (although its all for naught, since they were arranged to be married to each other anyway). Its just that The Little Mermaid piles up a lot of unsubtle allegory and doesn't even attempt to mitigate it.