It wasn't a very good measure of page speed anyways. For example the Microsoft dev site scores 83/100 and loads faster than any site I've ever seen before.
It sounds like you're talking about PageSpeed Insights? [1] That's not deprecated. This announcement is about PageSpeed Service, the Google-hosted optimizing proxy.
You're talking about a different service as an FYI. What you are referring to is Page Speed insights service which for the record is actually pretty amazing.