Ksenia is actually not an unrealistic contender.
First of all, as a junior she was on the same level as Daria and Maiia, and actually has a higher personal best then either of them. So if they're contenders so is she. (She's scored 215 internationally as a junior.) And while she wasn't overly consistent last year, neither was Daria last year. In fact Maiia still isn't.
Second of all, she was injured this year but Anna and Liza T had COVID/pneumonia, Sasha was injured, and Alena was both ill and injured so that's not a limiting factor and we all know that the Olympic team will be about what happens next year anyway.
Finally, you might be saying that she doesn't have an "ultra-c" element. But neither do Daria or Alena currently. And Maiia just landed her quads for the first time ever. And furthermore you would be wrong. Ksenia does have a 4T and 3A. She's landed both in practice and attempted her 4T in competition. She didn't land it but neither did Anna, Sasha, Kamila, or Maiia the first time. (And it took much longer to get consistent - Sasha's 4S and 4F still aren't consistent, Kamila's 4S still isn't consistent, Maiia's quads still aren't consistent, Liza still hasn't landed her quad in competition - I could go on.) Plus she has a 3Lz+3Lo combo which while not consistent either neither are Sasha's and Anna's - they've both struggled with that this year (and did last year as well). Plus none of the other contenders have a 3Lz+3Lo combo at all - and we've seen the advantages of the +3Lo combo when it comes to layouts and BV.
So no, she's not a tier 1 contender. But neither are Alena, Liza T, Daria, or Maiia. And no, it wouldn't take them regressing at all or having a serious injury for her to have a shot at all. She's already at their level (and actually already has a higher BV than Alena and Daria.)