I Love L.A. - Wikipedia
Yes its a parody of Randy Newman's "I love LA" being used as promo to get viewers to ABC during the 1985-1986 season. Also the I love LA parody was used in Australia for Nine Network during this same time frame. In the parodies they remove Los Angeles area references and put the shows that was on their network at that time.
Yes the original song has been used for decades to get the crowd to celebrate whenever a Los Angeles sports team wins on their home stadium during playoffs.