When they give figures of deaths, it's for all migrant workers and all causes of deaths. so if an Indian accountant has a heart attack and dies, that's a migrant worker death. In these thousands of reported deaths, many are from natural causes and many have occurred on construction projects unrelated to the World Cup.
You can certainly question the methodology of the Qataris in classifying these stadium-related deaths as being somewhat dubious but the fact that these deaths have occurred does not automatically mean that they've been a result of mistreatment, as journalists and others would have us believe. If you counted all deaths at work in the UK, regardless of the cause, the numbers would probably appear to be significant but correlation is not causation.
If you look at the situation at Twitter, where Musk is apparently giving out ultimatums about work intensity, many of the people working there who don't (or can't) resign will be migrant workers on H1B visas. Like the kafala system in the Middle East, these workers are absolutely tied to their companies and resigning effectively means the loss of their visa, and therefore their right to remain in the USA. Yet no one ever talks about that as 'slavery' or abuse of workers' rights.