A little confusion here - not as bad as it initially seems
Don't panic !
When your mac updates to the new iWork apps, it leaves the previous versions in place. So, they're not gone and if you found them useful a few days ago then nothings changed, they are just as useful and fully functioned as they were.
What has just happened? Well it looks like Apple has stripped back functionality so that the iOS, mac and the web versions of the iWork apps are 100% compatible.
I'd be surprised if they didn't start adding back in features to the mac version and bring those feature to the iOS and web version in lock step. It'll take time, but i imagine it'll slowly happen.
If it doesn't, they didn't remove the previous version
The one thing to watch out for is the new version will probably update the file format and make it impossible for the old version to open it.
However, if you are on a Mac, you should be using time machine and letting that back everything up so any old versions of files are accessibly anyway.
All this fuss, anyone would think this was FinalCutProGate!