Right! They've got the same thing going that ordinary LWRs do: the neutrons lose their energy in a surround liquid rather than in a solid moderator or solid structural materials other than the fuel rods (which are designed to be replaced often anyway). The design even adds some hafnium to the coolant salt (substituting for zirconium, which is the sacrificial metal you refer to there); hafnium serves to shield the reactor walls from thermalized neutrons.

One additional advantage of separating the fuel salt from the coolant salt is that the coolant salt volume can be increased as desired, making the thermal inertia of the reactor as large as one likes independent of reactor power or size of the fuel load.