Right now, it can dip back below yes. This is something I am thinking about changing because it can be a bit annoying sometimes.
If you don't change it, I recommend renaming it to "max". When I was getting close to infinity food for the first time, I moved everyone into food production, expecting that once I reached it I wouldn't have to worry about food again.
But I prefer the idea that reaching infinity means you actually have infinite and don't need to worry about it anymore. Also, I was expecting that each successive resource would take more, instead of all of them being a quintillion. That might be interesting, though it means that you'll spend a while with the game getting simpler and simpler, which is usually the opposite of what you want.