There is an updated pull request by pbui against master on the void-packages repository

https://github.com/pbui/void-packages xfce4-4.16
https://github.com/void-linux/void-packages/pull/27367

[RFC] xfce4-4.16
Updated core xfce4 packages to 4.16.0 as listed here: https://gitlab.xfce.org/xfce.  [ChangeLog](https://xfce.org/download/changelogs/4.16/)

Built and tested on x86_64.  Also built for x86_64-musl (but didn't test).

A patch file from https://github.com/void-linux/void-packages/pull/27367.patch is attached