^Yep, sure, Papikana shouldn't be paired with Cocona. It's not like she specifically says in the show not to call her that anymore post-memory return since she's not Papikana anymore but Papika. I saw it as less of a de-aging and more of being reborn, with those past memories akin to memories of a previous life that confused her for a time.
Also pretty certain the creators said in an interview it wasn't de-aging either to dispel that whole issue with Papikana, but my memory's not too clear on that one.