....
in theory, at low enough oil costs oil-fired plants can undercut other power producers, although i don't know enough to say what $/barrel cost (or length of time spent at those prices) it would take for his theory to play out.
He started with negative prices and he published this on the 27th of May, let's assume he is indeed talking about a long term trend..
BUT
For oil to compete as energy generation with coal you need a barrel of oil to be 4 times cheaper than the metric ton of coal, which although spiking lately was usually in the 30-40$ range so you need oil at least at one 10$. You have extra oil to burn, well, you also have a lot of coal and a lot of excess capacity in coal. Just the excess capacity in Scherer and Bowen could power 20% of the network. That's why you use in winter those oil powerplants because the energy gets expensive as an import from Canada decrease, hydro goes down, solar is almost dead but the gas consumption is also dead.
No, it needs too many stats aligned (and Trumps's tariffs to go away) for this to happen