They explain in the article that such minor stories rarely get follow-up, so you'll never hear if they get exonerated / found innocent. Whereas if, say, Bill Gates gets arrested, they'll be a lot more likely to post updates and further clarifying information.
Just from personal intuition, I'd also expect that a lot of sources would be name-dropping "Bill Gates got arrested" even if the AP tried to keep it quiet, so there's less value.
As noted elsewhere, you cannot be "found innocent". The accused is presumed to be innocent. They can be found guilty, subject to some standards based on the circumstances.
This misconception is precisely the reason for this policy change.
Just from personal intuition, I'd also expect that a lot of sources would be name-dropping "Bill Gates got arrested" even if the AP tried to keep it quiet, so there's less value.