Jester and Gamble aren't identical. There's a period in one, a semicolon in the other, and that can affect the scope of a clause. I'm not arguing that Gamble is clear enough as-is, just, I don't think I get anything from keeping Gamble worded the same but changing the ruling on it.
So maybe the period vs semicolon could make a difference to scope (I am not in that camp), but it doesn't matter - we just chose Jester as our example, because that was a clear case where the intent was that you should not gain a Province if the other player can't gain a curse. There are plenty of other examples* that use the "If X, Y. Otherwise Z.": construct: Tormentor, Leprechaun, Farmers' Market, Rogue...
* many of these other examples would involve edge cases - e.g. for Farmer's market, it would be if you played it with BoM or some other command card so didn't trash, Rogue if you used Trader to gain a silver instead, etc. - but I still think they're relevant.
I also don't think Gamble is like Jester and Tormentor, precisely because of "you may". Since Jester and Tormentor don't have "you may", they are not ambiguous at all. Gamble is ambiguous, but with the most natural interpretation probably being that you only discard the card if it's not a Treasure or Action.
I'm not sure why "you may" matters here... having something be optional is just one possible way that a card might instruct you do to something; but it's not the only way. What matters is that it's possible that you don't end up doing the action in question. If someone plays with Gamble first, and reads the FAQ for it, then it's completely reasonable for them to play with Jester later and think that the "otherwise" in Jester means "if they didn't gain a Curse".
Right. Imagine two cards:
"You may gain a silver. Otherwise, gain a Gold."
"Gain a silver. Otherwise, gain a Gold."
In both cases, you either gain a silver or gain a gold*, the difference is just that the former gives you the option, the latter waits until the Silver pile is depleted. The "you may" makes no difference in how you would interpret the "Otherwise".
* unless of course both piles are empty!
The time for me to change the card functionally in order to improve the clarity of the wording... was before it was printed! That was the time to do that. People had input then and the card was printed like it was.
When the card is reprinted, I can try to improve the wording, but I will avoid any real change to functionality, because it's much much better to not change the functionality. I reserve that for situations where the functionality is utterly messed up, e.g. Inheritance (not the case here), or situations where it's a significant edge case to get the difference to appear. Yes okay I also allow "keep you honest" fixes, which are not utterly messed up and do come up, but are extremely minor. Anyway there is not sufficient impetus for changing Gamble's functionality, so its functionality will not be changing. The wording could be improved though.
And, if it needed the small font, it could get it; now that the card exists, it's stuck getting the best wording it can despite what font size that entails.
Changing the wording, of course, also solves the consistency issue.