Not that it helps but the CEO claims they forgive for this type of attack/event. https://news.ycombinator.com/item?id=39521986

Netlify CEO here.

Our support team has reached out to the user from the thread to let them know they’re not getting charged for this.

It’s currently our policy to not shut down free sites during traffic spikes that doesn’t match attack patterns, but instead forgiving any bills from legitimate mistakes after the fact.

Apologies that this didn’t come through in the initial support reply.

And later they were asked if they would have responded if it didn’t go viral. https://news.ycombinator.com/item?id=39522029

Question:

There are only two questions everyone have:

1. Would Netlify forgive the bill if this didn’t go viral?

2. How do you plan to address this issue so that it never happens again?

Everyone here knew someone from Netlify would come and say OP wouldn’t have to pay. That was a given. Now we want to know the important answers.

Answer by CEO:

1. Yes. We’ve forgiven lots and lots of bills over the last 9 years and they haven’t gone viral

2. While I’ve always favored erring towards keeping people’s sites up we are currently working on changing the default behavior to never let free sites incur overages