This "news" is no surprise to anyone who's followed the Cubs' radio moves over the last year. When they signed a seven-year deal with CBS Radio to begin in 2015, they had the right to opt out of being carried on all-news WBBM 780 and move to WSCR 670 ("The Score") after one year.
That's now exactly what they've done, according to longtime Chicago media writer Robert Feder:
Chicago Cubs baseball broadcasts will air on WSCR AM 670 next year, according to a joint announcement Wednesday by the team and CBS Radio.