Hey, it wouldn't surprise me if all the USA newspapers everywhere were to go digital and cease from doing print editions.
I suspect a lot of papers keep their print editions because they have loyal subscribers who only take the print edition. Mostly seniors, but while their hair is gray, their money is still green. I'm not sure I know of any papers who employ carriers, with everyone choosing for delivery by the US Mail.
This inspired me to check my old hometown paper, who I competed with when I was in my first radio job. They used to publish 6 days a week. They had six full-time writers plus some stringers. Now it's two copies a week and one full-timer writer.
The AJC is one of the remaining media properties still owned by Cox Enterprises, along with the Dayton paper.
That's probably the real inspiration here. Paper circulation has likely declined to such a degree that it no longer makes sense to run the pressroom. Gannett, the largest newspaper chain in the country, has aggressively consolidated its presses, and Cox doesn't have the scale to do so.
Cutting back the days of print doesn't help this much. The press still costs a similar amount, because you still need a certain amount of labor to print a paper on time. The press employees are typically unionized and cannot simply be dropped from 40 hours per week to 24 hours.
For a sense of scale, I found a story from WABE that said the AJC presses produced 300,000 copies a day in 2013. The announcement today said they only printed 40,000 papers daily, a decline of 87% in a decade, despite a pretty large increase in population in the ATL area.