One possible example: their usual transactions to fill up the hot wallet are not going through because too low fees, or timelocks/multi sig issues, and now unex

One possible example: their usual transactions to fill up the hot wallet are not going through because too low fees, or timelocks/multi sig issues, and now unexpectedly they need to go to the cold wallet and this takes time. I bet they are doing waay more withdrawals today, many times over their usual volume so they are hitting some capacity issues, and you can't rush these things.