They had titled it The New Adventures of Wonder Woman by then if I recall. Originally the series aired on ABC and actually got decent ratings, but they wouldn't renew it because it was expensive to produce what with it being set in the 1940's.
The sudden timejump to modern day was CBS's condition on picking the series from Warner Bros, and to cut production costs. The CBS revamp actually caused Steve Trevor to be killed off as a result, however Warner Bros wanted to keep Lyle Waggoner around, so they brought Lyle in as Steve Trevor's son.