I haven't looked up the details, but it appears that from April 2022 pro go in Japan will become even more of a rumbly-tum game. Games with time limits under 3 hours each will now not stop for lunch or dinner, and games with over 3 hours will stop for a shorter lunch break and will not stop for dinner. I didn't check to see how this will affect two-day games, but I assume that it's going to be the same as for other games but still with an overnight break. If a game drags on beyond dinner time on Day 2, you just play on, presumably. This is a Nihon Ki-in rule change, but the Kansai Ki-in is expected to follow suit.

No reason was given that I saw. It doesn't take a lot of imagination to assume this is driven by the fear of using AI, but meals are often taken communally, so that assumption may not be the right one.

I thought that, in 2 day games, players were now required to go on lockdown. More severe than before.

I also thought that there was no break for dinner in day 2. In day 1, they finish before, of course. But perhaps this was not in the rules. It's only that, in the games I've watched to the end, games aren't usually that long. Byo yomi, it's common. But to the last minute... I think it's not common.

AI? Maybe not for the reason you said. My first thought is always money. Maybe it's too expensive with food price inflation yet every meal has to look インスタ映え. Just pack a lunch everyone.

Are the players allowed to eat while playing?

They do.

When they leave, there are lots of tays, cups,...