Listen, while she obviously needs to change from a girl in a bikini who only speaks in wind puns, I think it is vital that Janna still shows a lot of skin and remains "sexualized" when she gets visually updated. Being revered as some higher being or goddess is usually in nature for them to be "perfect" or "beautiful." This goes along with a lot of mythology where the purest beings are often naked or showing a lot of skin because that is the human's original form and that is way to show them to be beautiful. I'm not trying to say that in order for Janna to be viewed as a beautiful woman she needs to be naked and "slim-thicc" but the gracefulness and the overall higher presence of a primordial being added to her character would fit really nice by turning her bikini into the nudeness of ancient art and culture. I don't know what direction Riot is going with Janna, but since she already is mostly naked I would be very surprised if she was all covered up in her visual update to begin with.