The rules haven't changed, but I have tweaked the orange post to make a technical point I've gotten some questions on more clear regarding negative and double negative gpt.
The point primarily is this: just because you're losing money per turn, doesn't mean you're in n-gpt. N-gpt requires you be losing money per turn and not have the savings to cover the next turn's defecit. This is a subtle difference that affects whether or not you can give money to the AI.
Example one: (pure negative gpt)
You have no treasury and a budget status of -100gpt. You are not allowed to give the AI lumps sums or gpt.
Example two: (defecit spending)
You having a treasury of 1000 gold and a budget status of -100gpt. While this is defecit spending, you won't go bankrupt for 10 turns and you are allowed to give money to the AI.
The break point of legality would be when the treasury runs out. If you have gpt going to the AI at that point, you need to do one of two things:
1) Break the deal (declare war on any involved AI's), at which point negative-gpt would be legal.
2) Balance your budget (reduce sliders, abandon units, sell buildings, generate more income from other AI's).