My guess is this $2M may be the amount of tax paid on average over a lifetime that goes toward state services? So like a massive tax refund for life, but from a body they're not paying tax to, so they'd never actually accumulate anything to refund. Is that it?

~3.7M annual births in USA. That's $7.4T a year in secret citizen stash money. Maybe that's the real reason US life expectancy is much lower than other developed nations, the IRS doesn't have a vault big enough to cram the generational $~500T of wealth in.