These are new findings. You didn’t learn them in 1960.
That is just not true.
The article says that they were debunking a recent claim "made in a separate paper published in the same journal in 2018, which proposed that the toes might have been somehow retained within the (single) hoof."
From the article above you posted ...
solidify the longstanding understanding that these toes have indeed been entirely lost during the course of evolution.That means it was already long known and the new research only re-verified their understanding.