Seven million extra doctors' visits are hardly inconsequential, especially considering that only about 1 in 175 would actually be suicidal. Consider the time and money spent, the extra doctors who have to be trained and hired (I'm assuming psychiatrists since a GP is hardly qualified to assess a potentially suicidal patient), and the days missed from work for false alarms. That's all before the psychological trauma and loss of trust from your doctor telling you out of the blue that they think you might be mentally ill when you're not.
Besides, that's not how it would work, because once the tool is out there and used to profile everyone, someone who is suicidal will commit suicide before that 'extra session.' After that, it will be be considered negligent not to 'do something' immediately once someone is flagged, and that something would likely be intrusive and expensive.
Also, their accuracy rate is 67%, not 99%. I used that number to demonstrate a best-case scenario. As it stands, they would flag around 83 million people while only correctly flagging around 200,000. Good luck with 99.75% false positives.