She never wanted to lose her dick -- well permanantly that is. She tried to get rid of her confiment but it did not work.
And besides the whole heir thing-- which if it happens I also dislike since I do not like concept of companions punishing people for lacking in certain equipment ala Kiyoko -- she is still build on the premise that she is your subby girl. Now that can lead to a scenario where she could gain a vagina for champions benefit, but that is a premise that Savin never wanted to explore. Same reason how some people want Brienne to gain a dick but Wsan has no interest in it.
I know Ryn never made statement where they said " I don't want a dick. I want to be a real girl." or anything along those lines. Even in the old builds that I remember playing, the purpose of of shrinking their dick or growing a vag was to try and get the cage to fall off. But the cage basically shrunk with it or became a clit cage. So, yeah you're right, Ryn never says they don't want a dick.
My point was the way many of the scenes with Hethia or where Ryn told us about the bullying they received from their sister, it was heavily implied Ryn was being bullied due to them having a dick. (Originally I thought Ryn was a trap or boy but due to his sisters treatment had been sissified. And I thought the original purpose of the character was to appeal to people with a sissifacation fetish. But the character is just a chick with a dick.) While, yes Alissa is a massive bitch Ryn clearly has a complex about their dick. Both due to it being small, and how other characters treated her for having one.
The old Hethia scenes if I'm recalling them correctly, Hethia really lays into Ryn about that and if you have a confident Ryn she'll call Heathia out for her petty insults. As, Ryn came in good faith to negotiate the release of the loggers (probably one of my favorite bits of character development, as it showed Ryn won't allow herself to be pushed around anymore. It allows your companion to show their growth without undermining the pc's role as the protagonist. It's part of the reason why Ryn was one of my favorite characters when I first started to playing.)
While I don't know what Savin has directly stated or what they had planned for the character in the past, there is room for both dedicking Ryn or maintaining the status qou.
If you asked me as a writer, it makes more sense for a confident Ryn to keep their dick. It shows them overcoming their insecurities and accepting themself ( If you asked me as a pervert I would prefer a dedicked Ryn.) I don't mind a more confident making their own decisions every now and then.
If written well it could be interesting to see. But, there is room to write a storyline where a confident Ryn chooses to lose it out of there love for the champ. It's made clear both in sex-scenes and dialogue Ryn wants to the champ to be as happy, as they've made them. Both in dialogue with Brint, Arona and Cait its made clear Ryn looks to the champ for approval and even copies some of their mannerisms. It could also play into the whole story-line of them trying produce a heir. Maybe they say fuck what kingdom wants, I just want to have freaky sex with my lover. Or they consult you on the matter as they don't want to lose you. Outside of Brienne, Ryn comes across as like a true lover, that cares about you and what you think. In most healthy relationships people consult the person their with because they respect them and know certain descions affect both people in a relationship.
If were talking about a insecure Ryn, it doesn't make any sense for them to have a say. You should be completely in charge, even if Ryn takes the throne it makes more sense for you to be the real power behind it. And if you want to dedick them they have no real say. It could turn into a interesting corruption route.
The writers left certain traits about this character open, and I'm not saying this is entirely negative. (I don't expect any writer to tell us every detail about a character, but some of the choices seem questionable at best.) I genuinely believed Ryn had a lot of potential as a character, but now a lot of things come across as spiteful or deliberately done annoy people.