You got the main idea, it's a proof-of-concept: that a class of error-correcting code on real physical quantum chips obey the threshold theorem, as is expected based on theory and simulations.

However the main scaling of error correction is via surface codes, not repetition codes. It's an important point as surface codes correct all Pauli errors, not just either bit-flips or phase-flips.

They use repetition codes as a diagnostic method in this paper more than anything, it is not the main result.

In particular, I interpret the quote you used as: "We want to scale surface codes even more, and if we were able to do the same scaling with surface codes as we are able to do with repetition codes, then this is the behaviour we would expect."

Edit: Welp, saw your edit, you came to the same conclusion yourself in the time it took me to write my comment.