Being lost, I do not think so. In this case infos were lost only if we abandoned the current database instead of waiting.
I'll try to make a full backup tomorrow afternoon anyway. So if the site works and you want to update things, better do it before that
I have no idea if it will be down again in the next hours/days or if the problem is really fixed.
It seems that they will try to find a solution to prevent such problem from happening, we'll see.