Nope! Not for me by a long shot, I still think Yuna's change in X-2 is one of the worst things about X-2 as a whole. It was nice to have a strong willed & introverted character for one of the main characters in Final Fantasy - Yet S-E didn't seem to think this was possible to continue for Part 2 and I found it very insulting. Overall I don't mind X-2, it does have good gameplay (Apart from in order to get 100% you have to maintain your nose in a guidebook in case you any minute detail) and despite Yuna's character overhaul it can be fun/funny at times.
Whether Yuna’s representation in Final Fantasy X-2 is a good or a bad thing is certainly up for debate (I preferred her in FFX myself), but as far as I can determine she is definitely very different from her original character. I’m not just talking visually, because the hot pants are certainly not something the OG Yuna would have worn. In terms of personality she seemed to be different too.
Interestingly, Yuna’s VA (Hedy Burress) expressed similar sentiments upon seeing FFX-2’s redesign for the first time, according to her recent interview with KupoCon (approximately 3.09.00 mark).
That said, in real life people do change and it is plausible that Rikku’s bubbly personality had rubbed off on her. Yuna is trying to bounce back after watching her beloved vanish into thin air. Give her two female sidekicks and some giggle-gas and a newfound zest for life in a world free of Sin and I guess I can see how she started to act as she did. Yuna being different doesn't need to mean that she cannot be the same character, and if I was to replay it again with this thought in mind then I'd try to tease out whether this could be the case.