The propulsion isn't the main issue jet builders have faced to step in the hypersonic era, the aircraft resistance to heat is.

The solution lies in -simply- staying away from the heat...

Neither the article nor the video do mention that all these advances are made possible thanks to the use of Magnetohydrodynamics (MHD) : the art of isolating the aircraft's hull from the airflow with a layer of plasma created by the aircraft's hull when it reaches hypersonic speed. By setting an important network of magnets and running a very intense electric current on the hull to exploit the Lorentz force, it prevents the aircraft from the burning airflow.

1- The hypersonic airflow approches the aircraft's head and compresses brutally hereby heating at a high temperature where it becomes ionized thereby becoming electricity transmitting and so interacts with the network of magnets and electricity wires places under the hull.

2- The airflow transforms a part of its kinetic energy into electricity at the plane's front and thereby slows down. This happens because of the Lorentz force: interaction between a moving fluid that permits electricity, magnetic field and electricity.

3 - The electricity "produced" at the front is directly retransmitted to the air at the rear of the aircraft where the opposite process takes place: it accelerates the ionized air.

It works (I admit I haven't experimented it in my garage), it was achieved about two decades ago by the US, the Russian had exactly the same vision but at times of the fall of the USSR they never could find the budget to build it (the Ajax aircraft) and it went declassified : it is the reason why now more or less accurate infos about this technology can be found on the internet.

While the article's development about the propulsion is quite pertinent its title can be even better applied to that hull's plasma confinement.