I don't know that they hang onto CPI numbers either. I just worry that the negative headlines that the mainstream media (CNN, NBC/ABC/CBS Nightly News, Fox, local newspapers, online clickbait sites) will lead with, will shape people's perceptions that nothing is getting better. That high prices and economic despair will be here to stay. The more people are reminded of the high prices at the grocery store, the worse it gets politically. The news media covering the CPI numbers the way they have is yet another stark reminder of that economic despair.
It was part of the narrative around gas prices. Gas prices are high, so the media covers it with a doom and gloom, pain the the pump narrative. That narrative than shapes people who consume that media's opinions and beliefs, thus doing damage to Democrats in power. Gas prices go up, Democrats approval ratings go down. Inflation stays high and the news doesn't get any better on CPI numbers, so people swing back away from Democrats right before voting. So the worse or more negative the news media coverage gets, the worse things get for Democrats. Even if people feel inflation every time they go shopping, when the media beats it into their head that things aren't getting any better, that's when the real political damage can be done.
Maybe I am just being too much of a pessimist myself and piling on Democrats midterm chances with bad spin of my own. I just so deeply subscribe to the old James Carville philosophy of "it's the economy stupid" and that people's pocketbooks are what have in the past and will now drive the election cycle.