Yes, many mistakes in the article - some pretty funny.
A LFTR needs U-233 to start the reaction, as I understand it. Then Thorium decay cycle maintains the reaction with a minimum of resulting actinides. Not really a burner fast neutron reactor.
The TE IMSR looks like it will use Uranium decay cycle, so more actinides. Good for burning “spent” fuel is the thinking I suppose.
Any thorium-cycle reactor can use any fissile material that is available for startup....U-235, U-233, or Pu-238. The excess neutrons from that "starter fuel" then "breed" Th-232 into U-233, which continues the cycle until all Th has been converted and "burned".