Nenanah
It's in the ToS that Gaia reserves the right to do anything with the items that they want.
Everything is buy at your own risk, it's been this way since they started re-releasing the older MC items.
I'm not arguing that point-- I'm completely aware that all items are buy at your own risk; it's been that way far longer than that. Three words come to mind: Monkey/Bear Pajamas.
Yes, nothing was ever promised. Yes, they are completely within their rights to make whatever changes they want, up to and including making the payout for all golden lunchboxes be a picture of Lanzer's face with the word "SUCKER!" in flashing lights underneath. And no, we are never ENTITLED to anything. Not gold, not items, not refunds, not Lanzer's face with the word "SUCKER" in flashing lights underneath.
But the decision to make this specific alteration to the golden lunch box was not a good one, from a customer service standpoint. The goal shouldn't be "Discourage users from buying gold generators, or from choosing the 'Gold' option on these generators." It should be "Encourage users to select the non-gold options on gold generators, and to purchase other items." You can't make everyone happy all of the time, but you can still achieve a kind of equilibrium where most people are at least content. Contented customers spend more money. A customer who feels like they were "burned" by a previous purchase will be much slower to spend that money.
I'm willing to bet that a lot of Gaia's profits are from impulse buys, judging from the system they've fallen into for cash shop items. (Quantities are limited, so buy now! This is only available for 24 hours, so buy now! Here is a special discount for cash for today only, so buy now! ) Hesitant consumers are the LAST thing they'd want.
But as far as I'm concerned, I just don't like the "serves them right" reaction to customer complaints over the change in the lunchboxes. I roll my eyes at the more entitled-sounding people too. But whether or not you agree with it, and whether or not Gaia had every right to do so, a significant change was made to an item that a lot of people bought, and they are understandably disappointed by this change. And they're allowed to be.