I figured pastors have some choices, depending on their experience with the congregants. Our congregation is mostly older of German heritage. Lots of good food at the potluck dinners.
When a festival falls on a Sunday during the “green season” (the non-festival half of the year; ordinary time), it’s OK to do that festival in place of the regular readings. And with one of my two congregations being named St. Matthew, I could hardly not do his festival.