It doesn't really have negative implications for MSRs in general. It's just one design out of many.
The debunked claim is just that they could get uranium fuel utilization comparable to a fast reactor, using a reactor operating mainly in the thermal spectrum. None of the other projects make that claim; either they actually are fast reactors (Moltex, Terrapower), they claim much lower fuel utilization (Terrestrial Energy), or they plan to run on thorium.
Your first-order mental model should be that (1) thorium requires breeding and that works in a thermal spectrum, (2) uranium doesn't require breeding if you're content with fissioning U235, and (3) you can have a breeding uranium reactor but that requires a fast spectrum.
India and China need thorium power. It is non-proliferation fuel and is abundant in these two countries.
It could be the biggest factor bringing down pollution in the world's two fastest growing economies with massive demand for power.