When KABC last week moved talkshow host Michael Jackson to a weekend slot, they apparently neglected to tell the host he’ll replace: Susan Estrich.Until last weekend, Estrich, the USC law professor and presidential campaign manager for Michael Dukakis, held down the 10 a.m. to 1 p.m. shift on Saturday and Sunday. Last Thursday, Jackson announced on the air that he was moving from his weekday shift to an unspecified weekend slot. However, nobody at the Disney-owned station bothered to inform Estrich, who discovered the change the following day when a reporter called her for comment. “What makes this particularly odd is that I have very warm and cordial relationships with many people on the Disney side,” Estrich said. KABC failed to return phone calls seeking response.