The timing of the failed test and the wedding makes sense. I get that it's the athlete's best interest to not have a Fed file on behalf of the athlete, so that it's coming from the athlete's mouth, and that even had she filed for retirement with the Russian Fed, it wouldn't have trickled down officially.
What's odd is that if she'd missed multiple tests after she'd retired definitively, wouldn't RUSADA have left a note on her door and/or sent her a letter or email to notify her or the Russian Fed that she'd missed a test, and that, at least after the second one, she'd think that she needs to get herself off that list? Or do they keep it under wraps until they bust the person or track the person down at someone else's house?
The worst case scenario should have been that she knew she'd failed the last drug test and that pushed her into retirement, instead of leaving it open-ended. If she had rolled with it, she'd be facing two years suspension while retired and completing her GITIS degree, and then, after her suspension was over, and she had her degree, she'd be hired as a choreographer, because she could say, plausibly, that she was retired, took the drug to lose weight for her wedding as a one off and messed up the bureaucratic stuff. Now she's likely barred from rinks for a decade.