Every sentence of this is wrong.
Disclaimer: I am no fanboy of Tesla; I think Tesla's lunch will be eaten by BYD, either alone or together with other Chinese EV manufacturers, in part because Tesla has been resting on its laurels for so long (still selling the model S!); but facts are facts.
> But battery research is ongoing from a century...
Tesla's claim is about motors, not batteries.
Tesla has implemented solutions that no one else has, such as their "two casting chassis", which Toyota engineers recently called " a work of art" and "genius". The 4680 cylindrical battery is also a Tesla innovation.
> It is most certainly a trade off...
It is not clear at all whether this announced motor is a trade off. It may be the way ahead to further improvements in the space of EV motors. More detail would be good to have; that much is true.
> Moreover, lithium-ion batteries...[lithium] is the bulk of the battery.
Again, this is about motors, not batteries. It's eliminating the neodymium and other "rare earth"[1] elements used in the permanent magnets present in nearly all EV motors to date. No EV motors use lithium in significant amounts.
But the numeracy nazi in me must also point out that when it comes to batteries, there is more nickel than lithium, by a considerable margin, in NMC and NCA (nickel-manganese-cobalt and nickel-cobalt-aluminum) lithium-ion batteries. There is more iron than lithium in LFP lithium batteries. And depending on construction, there may be still more copper.
1. "Earth" is a now-obsolete term for "ore". These metals are not rare, but they spread themselves around, so economically minable ore bodies tend to be hard to find. The metals are not rare, but their earths are.