I don't believe this is anything sketchy. This happens to coinbase when the coins they have on their exchange go crazy. Their systems just cannot keep up with the spike in volumes. The same thing happened about 6 or 7 months ago when ether was spiking up and down.

They even decided to make good on ether trades that customers stopped out of when the price went down to 10 cents. Something I believe they didn't have to do and it cost them millions. They wanted to keep their reputation in tact.

What they are doing today is trying to prevent a bigger problem. Even though it is very inconvenient to their customers.