A number of deprecations were removed in Spring Security 4 to clean up clutter.
The following is the final commit for the XML and JavaConfig deprecations, which contained 177 changed files with 537 additions and 5,023 deletions: https://github.com/spring-projects/spring-security/commit/6e204fff72b80196a83245cbc3bd0cd401feda00.
If you are using the XML namespace or Java-based configuration, there are many instances where you will be shielded from deprecation. If you (or a non-spring library you use) do not use an API directly, then you will not be impacted. You can easily search your workspace to find these listed deprecations.