And I don't know if things change while beans sit around, but I can tell you that we each had a big bowl of soup and have been unfit for the companionship of other humans since.
I'm not an expert on this subject....however, I buy my beans when they available from Rancho Gordo or Purcell Mountain Farms. They are very fresh, according to what I have read on the sites. When I get them, I store them in the fridge. I rarely soak them, but if I have had them for several months, I do a quick soak for a couple of hours. We never have an issue with them.
Now, as to when the beans are in season is questionable. I've asked both places about it and they tell me each bean has it's own season. Plus it depends on what they plant and when. Both said, they sell out fast with most varieties, so the beans are always very fresh. They cannot offer a schedule of when they harvest. Since I usually buy several varieties, I know that some are over a year old when I finally finish the 1# bag. I've noticed that many times Rancho Gordo will have "very fresh" in the description section, so I assume they were recently harvested. Then there is a process they go through before they are ready to ship, and that time varies.