I think this shouldn't be taken too seriously, from what I understand it's an exploration of what's possible with today's LLMs.

You're right to talk about the trend though, because what it shows is how the cost of re-writing well covered project has completely crashed, so that in itself is a learning.

The cost of surface level rewrites has crashed. Which will probably cover 80% of cases. Caveat emptor on which side your project falls.