It was a big surprise for me.
Downloaded Android 5 on my 2012 Nexus 7 and Quick Office was totally gone.
Replaced with Goggle Docs, Slides, and Sheets.
A saw no announcement for this.
Google specifically said in an earlier announcement that Quick Office was going to be replaced.
It was going to be removed from the Play Store and get no more updates.
They also said that if you already had Quick Office you could continue using it.