Is it permissible for the Imam to instruct latecomers to the Eid prayer and sermon to hold another sermon and pray?

It is sunnah to make up the Eid prayer for whoever missed it with the Imam. As for the Eid sermon, it is a sunnah; it is not obligatory to attend it, listen to it, or make it up for whoever missed it, based on the hadith: "Indeed, we are delivering a sermon, so whoever wishes to sit for the sermon, let him sit, and whoever wishes to leave, let him leave."