I'd guess they found ratings to be the best in the evening instead of mid-afternoon.
Seems like they do this every year for Sunday of the first weekend.
They do it on Saturday too. When CBS had all the games they wanted to end by 7 p.m. eastern on Sunday as to not delay the start of 60 Minutes. But when TBS/TNT started to air games they moved games to late afternoon and evening. The biggest problem was playing the games yesterday in Salt Lake City starting at 10:45 a.m. local time and playing games in Pittsburgh that started and ended late into the night. That makes no sense at all but this is the world we live in today.