I am not sure where you got that idea. There is a very detailed post about the database and server issues, what they are doing about it, etc.
You can read all the details here
https://us.forums.blizzard.com/en/d2r/t/diablo-ii-resurrected-outages-an-explanation-how-we%E2%80%99ve-been-working-on-it-and-how-we%E2%80%99re-moving-forward/28164/3
It will be a while until fixed. In the mean time we have queues. Instead of server down for everyone for 4-5 hours, we have to wait to log in.