Oops I forgot about Tour Down Under on the same day. According to the TDU website, broadcast times for the cycling on January 19 is:
Sydney and Melbourne 12pm on 7mate
Brisbane 11am on 7mate
Adelaide 11.30am on Seven
Perth 9am on 7TWO
This suggests the WBBL semi-finals will be shown live on 7mate in Adelaide and Perth, and main channel on Sydney, Brisbane and Melbourne.