The network already has a system in place to combat this issue - fees. So it can technically cost $1MM to mine 1 BTC while the price of BTC is only $8,000, as long as the transactions provide enough fees to offset the costs. In practice I think that's pretty unlikely to work out that well, but that is the intended system either way.
Edit: Reading the article again, it's not clear to me they're actually taking halving into account in their calculation, and I'm also not extremely confident they're not confusing bitcoins and blocks. There are no direct quotes detailing that part of the article, and I wouldn't really expect the person writing the article to know the difference.
And it also occurred to me that something else to take into account is that miners themselves are betting on the price of bitcoin going up. So just because it cost them, say, $200,000 to mine $100,000 worth of bitcoin, if the price of bitcoin eventually doubles from the point that they mined them then they would still break even, though not immediately. So it can make some sense to mine bitcoins at a bit of a loss. I don't think it would make sense to mine at anywhere near the losses they're describing though.