I guarantee this is a management issue. Somebody needed to bear down at some point and put the resources into load testing. The engineers told them it probably won't be sufficient.
I assume this came down to some technical manager saying they didn't have the human and server resources for the project to work smoothly and a VP or something saying "well, just do the best you can.. surely it will be at least a little better than last time we tried something live, right?"
I think there should be a $20 million class action lawsuit, which should be settled as automatic refunds for everyone who streamed the fight. And two executives should get fired.
At least.. that's how it would be if there was any justice in the world. But we now know there isn't -- as evidenced by the fact that Jake Paul's head is still firmly attached to his body.