Hm… This reminds me I haven’t had this problem in a good while for now.
A few months ago I’d get this every now and then and apparently there’s no known solution for it.
It’s probably caused by some server instability.
Except there are no reported outages, so not sure why you’re so certain it’s Blizzard’s fault. Perhaps your ISP is really bad at routing your traffic… as is the case with most people reporting disconnections on the forum. How about some networking tests to prove what experience you’re getting? Did you follow any of the steps in the troubleshooting thread?