That was also a pebble bed reactor. The kind of reactor generating all of the latest hype is a molten fuel salt breeder reactor. There's a really substantial difference between the two and the MSRE was basically a mock up of the core running on Uranium fuel salt that would have been generated in a fertile Thorium blanket salt around the core and been reprocessed into the fuel salt.
Pebble bed reactors have tons of drawbacks that don't apply to most modern Thorium reactor proposals. The biggest drawbacks to proposals like e.g. LFTR is corrosion risks which were largely addressed by the MSRE ages ago, and the chemical reprocessing equipment which again is mostly a chemical engineering problem more so than a nuclear engineering one.
Pebble bed reactors have tons of drawbacks that don't apply to most modern Thorium reactor proposals. The biggest drawbacks to proposals like e.g. LFTR is corrosion risks which were largely addressed by the MSRE ages ago, and the chemical reprocessing equipment which again is mostly a chemical engineering problem more so than a nuclear engineering one.