Guessing…
Being a YC company¹, presumably the overlap with people who are aware of both is quite high. They also pay some "big names" an advance to write², and again the overlap of chosen people/interests seems likely to align to some extent.
FWIW, there was a time when the front page basically felt like a Medium indexer, and I imagine this cycle will eventually be the same as the platform changes/dilutes/grows(delete as appropriate).