This time last year, Michael De Luca and Pam Abdy were battling persistent reports that they were on the way out as heads of Warner Bros. Motion Picture Group, having made too many pricey bets on risky films. That made the studio’s triumph at the 98th Academy Awards on Sunday all the sweeter, as Ryan Coogler’s “ Sinners ” and Paul Thomas Anderson’s “ One Battle After Another ,” two of the films that had the Hollywood rumor mill buzzing, dominated the ceremony. “One Battle After Another” scored