About deprecations in this version of Puppet
This version of Puppet is not included in Puppet Enterprise. The latest version of PE includes Puppet 4.10.
The 4.x deprecations focused on Puppet’s infrastructure, and APIs, many of these have been removed in Puppet 5.
You should read through the removals in Puppet 5 release notes to make sure they won’t break your setup before upgrading.
Each deprecation page groups similar features together, and each feature explains what to do if you’re affected.