My conclusion is I think very similar to yours.

There are many problems with how migrant workers are treated but we don't know enough to conclude even roughly how many excess deaths were caused. But Qatar's lack of information provision forces us to assume the worst.

There is enough to criticize Qatar about without firmly stating a specific number for migrant deaths. And imo focusing on this misleading statistic of migrant deaths will undermine all the valid criticisms of Qatar.

I think people see that there are great problems with the working conditions and such in Qatar and then accept that number of deaths which everyone else is repeating, without really thinking about what a normal number would be.

The probability of death for an Indian man aged 25 over the next 10 years is 1.8% according to the data here.

That is for all men, not just healthy which you would expect migrants to be. But most men aged 25-35 are quite healthy I imagine.

Twitter has always been surprisingly small.

I think it is just not nearly as popular outside of the English speaking world.

Or maybe people just mostly see tweets shared on other social media rather than using twitter directly so it's impact is bigger than what its active user numbers imply.