Assuming that's true. It could be argued that she was just doing badly (and she was) and decided she couldn't be bothered to go through with it. This was a team event and she let the team down. The mental health could plausibly be just an excuse.
Not saying this is the case but it's certainly plausible as an explanation.
I think if you want to question people that are talking about mental health problems, and suggest without any evidence that they are making it up as an excuse, then you are going to do serious damage to people. It was'badly' in comparison to her standards which are the highest of all time.
And there is of course Piers Morgan has attacked the 'weakness' of Naomi Osaka, Emm Radacanu, Simone Bilex, and Meghan Markle but defended Paul Gascoigne, a wife beater for his mental health problems, and of courss Piers stormed off a TV when the weatherman questioned him. I wonder what the people he has attacked on this subject have in common, that Paul and Piers don't?