`@angular/platform-server`?

While updating an old Ionic 2.3.0 app I noticed that the dependency for @angular/platform-server was removed.

After a bit of research, I found this commit that made the app base ready Ionic 3.0.0:

Angular is updated to 4.0.0, all the other dependencies are updated as well - and the @angular/platform-serve dependency is just dropped.

Can someone explain why this happened?
Was this a Angular 4 thing?

If I remember correctly Angular 4 moved some stuff around, and changed what platform-server does.

I could only find this (not very good) link about it:

so from now: @angular/platfomr-server is for server side rendering of Angular and generating HTML pages(in NodeJS)

https://stackoverflow.com/a/42885233/252627

Hope someone else can provide a better link.