Based on the wikipedia article, macroscopic laser cooling is largely used for cooling gases.
Insofar as I'm aware, laser cooling is always used as the final stage of gas cooling, on top of more standard methods, because there are more efficient methods to go from e.g. room temperature to cryogenic temperatures, and cryogenic to near-absolute-zero temperatures and so on. The method in the article, as I understand it, is meant specifically to address the cooling that's typically done with e.g. liquid nitrogen and liquid helium, not necessarily what's done below Helium-4's condensation temperature. The article is definitely too vague to know if thermionic cooling addresses a Helium-3 stage or not.
Insofar as I'm aware, laser cooling is always used as the final stage of gas cooling, on top of more standard methods, because there are more efficient methods to go from e.g. room temperature to cryogenic temperatures, and cryogenic to near-absolute-zero temperatures and so on. The method in the article, as I understand it, is meant specifically to address the cooling that's typically done with e.g. liquid nitrogen and liquid helium, not necessarily what's done below Helium-4's condensation temperature. The article is definitely too vague to know if thermionic cooling addresses a Helium-3 stage or not.