Makes sense - gives value to the SEC and Big 10 championship games. The winners of those two get a first-round bye - the other 12 play first round games on the higher seed's campus. And the playoff is seeded based on overall rankings - and not having the top 4 based on any pre-determined formula for conference champions (other than the SEC and Big 10).
https://www.cbssports.com/college-football/news/big-ten-sec-set-to-unveil-grand-plans-for-college-football-playoff-change-but-is-anyone-else-on-board/