There are just two rare earth magnets of economic merit today:...

There are just two rare earth magnets of economic merit today: common NdPrFeB and rare SmCo.
While magnets can be made from any REE elements (because they all have electrons with unpaired spins; more than any other elements), those are the ones that came out on top after decades of research.

From a practical viewpoint, Nd and Pr are also the only rare earth elements abundant enough on Earth to play a central role in mass production of millions of motors. Sm-based magnets are for niche mission-critical applications only.

China will continue to produce additional grades of their REE magnets and will continue to learn how to further thrift NdPr by replacing a portion with LaCe (already being done to some extent), as well as learning how to thrift the "expensive dopants", namely DyTb (also already being done and very effectively so). These magnets are not expensive; there is plenty of room for them to increase in price.

China has been working on their REE magnet monopoly for many years and it is has now put them in the driver's seat of the global economy. They will be vacuuming the wealth of the Earth whilst driving the climate change agenda in an NEV. The current trade imbalance is trillions per year and substantially offset only by their importation of silicon chips.

NdPrFeB is the only practical choice for high power density magnets and the Chinese are the only ones mass producing them. It's not even close. And there is no substitute on the horizon. The US has poured a lot of money into futile high-tech national research projects trying find a new magnets; they just don't come around that often and there is a limit.

The current situation is alarming and many people, including many politicians, will stoop to selling false hope to the desperate to make money or to make themselves look good so they can stay in power; I suspect FeN is just that.