I don't think they are coincidentally doing that during the crash. Perhaps, they are doing some upgrade or maintain their website so they can run properly. But if they do that for some purposes, I think people will know, and they will choose what they need to do. Coinbase itself will try to fix the problem as soon as possible, and I am sure that they don't want to see their customer disappointed with that experience.

But we don't know what the truth about that is, and we can only guess. But we hope that Coinbase will be fine like before so you can use Coinbase as what you want.