That is correct that they don't use arsenic for many years now.From what I understand, all newer "pressure treated" lumber should now be fine for use in gardening as they use Copper vs Arsenic these days. I don't think you want to drink the chems directly, but incidental contact through soil transfer should now not be the concern it was back when they were using Arsenic 10+ years ago.
Would need to do some reading, but that is my recollection.
That said, they are still injecting these wood boards with chemicals. Fewer chemicals in you body is better.