If the companies got lured into using MongoDB as a service, then I understand that prices could increase and companies could be in a pickle. But if companies got lured into using MongoDB as software, I don't see how they could have a problem.
The parent comment states "their sales people started coming around and asking for insane sums of money" but I can't find any reference to this.
If MongoDB really is sending salespeople to make claims against companies who they convinced to use their OSS database as a data-store, than they are indeed abusing their license and no one should use their database or support their company.
From what I read of the license, that shouldn't be the case though.
The only major change to the license is in adapting to the rise of cloud services.
That's one of GPL's biggest strengths.
Also successful software packages that are GPL are GPL for everyone. You don't have a mother company that can bypass the GPL due to them owning the copyright. And when you do it's usually a scam that people can smell.
You can't say about a license change that it is in the "spirit of GPL" when the mother company, MongoDB Inc, doesn't have to play by the same rules as everyone else.
So I'm sorry, but when you're talking about the "spirit of GPL", you don't know what you're talking about.
The FAQ for the license change very clearly indicates that your reading is what was intended. Question #4 particularly contains the complete text of the section that was altered, and it's hard to see how they could have left themselves any room to penalize regular users.