Maybe I missed something here, but couldn't steam just sends stats to steamspy without any user information? That is if steam see any value in steamspy of course.
Exactly, if Valve cared about it they wouldn't even have to send it anywhere or even make it available via API, they could simply release it themselves. They have that information and worlds more, all 100% accurate.
Valve just doesn't care, they don't care about much these days. These privacy settings changes, just like their refund system, are due to EU laws.
The privacy change is for the better, any such information should be private as a default state without any "terms and conditions" attached to maintaining it, unfortunately it takes laws for such decencies to be the norm.
Though it is unfortunate to lose Steamspy as it's not just interesting and informative to users, for small and independent devs who have to make important and intrinsic decisions it's important having access to such statistics. Such things easily effect the type and success of games.
Still I suspect the title of this threat being correct is pure chance. While privacy laws are the actual reason for the changes made by Valve, Valve could extremely easily make that information available via many ways.
This is typical Valve fashion, Steam is the harbour of in Indie Games yet doesn't provide the world of information that could drastically effect what the indies do, not to mention their chances of success, which would in turn benefit Valve, and in the long term even the industry.
Also would like to congratulate an earlier post displaying incredible cognitive dissonance without even realising it, it was quite the stunner.