With so many stations going with newscasts (more on that in a minute), I wonder if fewer shows will make their way to NATPE in the future. I think there's still opportunities for 9am-noon and maybe 1-3pmish, but yeah, 4:00 news seems to be a thing across the country. I'm seeing 7:00 newscasts become a bit common as well. Besides, as Tim mentioned, some stations are double-running shows that already have a double run. Case in point: Judge Judy airs new episodes here from 6-7pm...an hour of reruns also airs at noon.
With a narrowing window, I can't see there being as much need for syndicated content, and could see more stations doing in-house talk shows or even game shows, syndicated through the ownership group, a la Let's Ask America. You have companies like Gannett that like streamlining content; I could see them doing something similar.
Around here, we have:
WVEC: 4:30-7am, noon-1pm, 4-6:30pm, 11-11:35pm, TOTAL 6.5 hrs
WAVY: 4:30-7am (with additional news on a sister station until 9am), noon-1pm, 4-6:30, 11-11:35pm. They also air a local talk show from 11am-noon, TOTAL 8.5 hrs
WTKR: 5-7am (with additional news on a sister station until 9am), noon-12:30pm, 4-6:30 (also a 7 and 10pm newscast on sister station), 11-11:35pm, TOTAL 8.5 hrs
WVEC used to have a sister station called LNC, which stood for Local News on Cable. It was a 24-hour operation, but technically only aired live when WVEC had a live newscast. Outside of the 10:00 news, LNC was mostly reruns of the WVEC news until the next live broadcast. It folded five years ago, mostly due to the economy. In spite of that, I think it probably ended five years too early, given the current landscape. IMO, it's probably the one reason WVEC doesn't air more news during the day -- they no longer have a sister station.