I feel like we've all gotten used to RusFed's tactics, so for them to prod another skater up (whether fairly or unfairly) isn't surprising. As dominant as 3A are, some non-Eteri supporting judges may not like that the entire Russian team is just her pupils. Politics may then come into play. Given that, the #3 Eteri senior would be the most likely one to get the boot if RusFed wanted to play some games. From what we've seen so far, there's really no way Sasha would get the boot. She's been far too consistent on her quads and has been scoring monstrously. Prior to Alena's 3A's, some were speculating she would get left behind. Now that she's added 3A's and gotten her well deserved PCS boost, it seems unlikely she'd falter. Lastly, that leaves Anna. She's senior national champion and I don't think anyone is discounting her, but of the Eteri new seniors, she's been the weakest by comparison. She's gotten hosed in the SP. She's fallen on a StSq. She's the only one among the trio to not score over 230. If she does happen to falter at Nationals, I would not be toooooo surprised to see them prod up a perfect Alina or Evgenia. Temporarily, Evgenia's SB is only 2 less than Anna's. Alina in the past has also scored much higher than Anna's SB. If RusFed wanted to play games, her spot would be most precarious. However, I don't think it will happen. Anna so far seems most likely out of 3A, but the chance is still low (if Sasha/Alena's chances of getting left off were ~10%, Anna's would be like 12%). Sasha has TES while Alena has PCS (and now TES as well). Anna is more in the mid ground, but has been judges less generously by comparison.
However, I don't think the conspiracy is as extreme as a lot of people make it out to be. I don't think Anna or any of 3A will be deliberately underscored. Only in the event that one of them skates underwhelmingly would someone swoop in and seize the opportunity. It would be foolish to deliberate shove down someone when they could theoretically sweep the Worlds podium.