That's happened before, though not to this scale. If I remember correctly, Rika Kihira herself was a last-minute host pick at NHK in 2018. She would end up winning the event and even the GPF. This competition's results were nuts though.I'm looking at the wikipedia page and what I find REALLY interesting is that BOTH Rinka and Starr were replacements. 2/3 of the medalists were replacements.
Let that sink in.