They underestimated nothing. Anyone with half an ounce of intelligence could see that having millions of people login simultaneously was going to have bumps in the road.
Blizzard likely even foresaw the sh*tposts and whines from a minority upset that their highly unoriginal name was taken.
If anything, I tip my hat to Blizzard. Compared to other times in WoW history where there has been millions of simultaneous logins, this was pretty smooth.
They literally never said anything like that. Reserving your character name early was a perk given to current subscribers. Just because you decided to subscribe for this ONE day, it doesn’t mean that Blizzard asked you to. Take some responsibility for your choices rather than blaming everyone else for how you spend your money.
What exactly does “ready” mean to you? The servers aren’t meant to sustain the ENTIRE population of each realm being online all at once. Literally the only time that happens is on launch days, and if you had taken a hint from WoW’s 15-year lifespan, you’d know that this is an inevitable issue every single time.
What should they have done? Increase their server capacity by 10x just to handle a one-hour rush of traffic that will taper off and never be that big ever again? This kind of thing was inevitable.
Regarding the topic: Why did Blizzard underestimate Classic?.
Answer: They didn’t. It’s players who cannot get their way, when they want, at the time they want it, that are the ones trying to say there is a problem.
There’s only 1 high pop server. There’s never going to be another time other than launch day where people are trying to all log in at the exact same time.
It was actually a brilliant move by Blizzard to allow name creation. It literally gave them a snap shot of how many accounts to expect and what the server size needed to be to accommodate those accounts. Sure we have layering, but with that also dictates how big the server needs to be to add more layers.
I agreed, this is lack of preparation. They have the infrastructure and have done how many stress tests? and they couldn’t get the name reservation working correctly?