Unless I'm totally missing something, there's no way to add a row to the homescreen that displays the newest releases of movie library(ies).
Would be a great, useful addition to latest media to have an option that sorts by release date instead of date added.
TLDR: This will be in Emby Server 4.8, and actually, it doesn't require a server release, so you'll start seeing this option in Emby apps sooner than that.