I understood deadnaming to generally pertain to gender identity. I don't think it's far-fetched to initially consider Asahi Lina's name as a Pseudonym/Alias/Pen-Name, as many creatives (authors, artists, musicians) have been doing for hundreds of years.

If it is a gender identity decision, I still don't view it as malicious for the OP to ask. The context just isn't there in the blog post to make that clear.