There are two other reasons for newscast expansion:
First, in many cases, the cost of expanding news is minimal, as in many stations, no new people need to be hired. The expanded newscasts are almost entirely 100% profit.
Second is political ads. Not only is there record TV ad spending for the upcoming (November 8th) midterm elections, but I wouldn't be surprised if some candidates decide to formally announce their candidacies for the 2024 presidential nominations of their respective parties before the end of this year (2022), perhaps just weeks (or even days!) after the midterm elections.
Such candidates (and outside groups running ads to promote certain candidates) may start running ads as early as next summer (June/July/August 2023), especially in early voting states like Iowa and New Hampshire (Boston TV stations, close to the latter, will also benefit).
Political advertisers love to spend money on commercial spots in news programs.
Indeed, especially if President Biden decides against running for re-election, I can forsee 2024 being the first $10 billion presidential election (in terms on money spent), with most of that sum being on TV commercials. Assuming Mr. Biden indeed doesn't run again, I can see the nominees if each major party spending $2 billion each in TV ads with outside groups supporting the Democratic candidates (including the eventual nominee) spending $2.5-$3 billion on TV ads and outside groups supporting Republican candidates (including the eventual nominee) spending another $2.5-$3 billion on TV spots (this includes the primary season as well as the November general election). And candidates who don't go past the primaries will spend hundreds of millions of dollars more during the time they are actively campaigning.
The bottom line: In much of the country, it may be difficult for non-political advertisers to even buy any TV spots for much of 2024 (especially in the weeks prior to primaries in certain states and the general election) as political TV ad spending will spread beyond newscasts to any sort of local commercial spot availabilities.
Should that happen, many advertisers may have to adjust ad campaign plans for 2024 (read: less TV ad spending prior to Election Day) and the major Detroit automakers may have to delay introducing their 2025 models until after Election Day as it may be all but impossible for them to buy TV spots in some areas of the country in the six weeks prior to Election Day for the reasons I outlined above.