The ‘'play through your own division'' is outdated, and the 2023 playoffs are a prime example of that. For reference, some of the second round matchups:
In the West, the Vegas Golden Knights and Edmonton Oilers were one and two in their conference, but are playing in the second round while the 4th place Dallas Stars play the 7th place Seattle Kraken.
And in the East, the 2nd seeded Carolina Hurricanes and 3rd place New Jersey Devils square off in one series, as the Maple Leafs (4th) get the Florida Panthers (8th).