Ok, I was a little surprised I must say, and to be frank in panic for few minutes, when updating, until I realized I had to remove from my app.yml all plugins that are now in core. May be I missed that change was going to take place ?
Surprised as you are that some core plugins that I am not going to use are in my install now (that redefines what a plugin should be no? 
), but the main point if it does not impair my site’s performance… why not…