Is it possible that Plushenko asked her to leave? Well not directly asking her, but maybe he's given her some type of an ultimatum? I mean looking at their statement, it seems like they're kinda happy (maybe even relieved) that she's left. As sad as it sounds I do understand why they would want her to leave. Aliona was a very expensive and costly business for Plushenko, with basically no gain in return.
Let's look at it this way, Aliona was not training at a public club. Maintaining a private ice rink cost a lot of money. I remember people here saying Aliona shared ice time with only few people (if any), it is cool but it is very expensive to provide private ice time for skaters. There were also gym expenses and other off ice training facilities. Of course all those coaches were not working for free either. Plus getting two programs from a very expensive choreographer.
Aliona has sponsors, but I don't think she's earning as much as Evgenia to cover all her training expenses and coaching fees. Plushenko must have covered part of it.
I understand why they want health certificates from now on. As cruel as it sounds, they don't want skaters to waste their money and resources.
Sambo club is different, it's a public rink so people can freely take their time and use the resources to get in shape.