Alex Moss

Peadig

Disables the default notification email sent by WordPress for an automatic core update. Simply activate the plugin to disable the notification email 🙂
<ul>
<li><a href="http://peadig.com/wordpress-plugins/disable-wordpress-core-update-email/" rel="nofollow ugc">Disable WordPress Core Update Email</a> Plugin homepage.</li>
<li>More <a href="http://peadig.com/wordpress-plugins/" rel="nofollow ugc">WordPress Plugins</a>.</li>
<li>Peadig: A <a href="http://peadig.com/" rel="nofollow ugc">WordPress Bootstrap</a> theme framework.</li>
</ul>

Disable WordPress Core Update Email

The simplicity of the plugin helps it be lightweight & easy to use.

That also means the one line of active PHP code that it consists of (it then being what WordPress recommends in its current documentation per https://wordpress.org/support/article/configuring-automatic-background-updates/#disable-emails-via-filter) is likely to continue to work exactly as expected unless WordPress were to completely overhaul its setup regarding this (with there appearing to be no plans for this.) Especially considering it's using a filter so it's even more flexible if things were to change in the future (won't outright break things due to a code error beyond WordPress doing a fundamental change to a core function like add_filter or __return_false & that'd then break the majority of plugins & themes out there [they'd need a good reason for doing so & it appears they obviously have no plans for doing that either.])

Does exactly what it says it does (even 5 years since last update)

Disables the default notification email sent by WordPress for an automatic core update. Simply activate the plugin to disable the notification email : …

Johan van der Wijk

This plugin disables all WordPress updates (core, plugins and themes). This can be useful if you have multiple environments such as a live and staging server and you don’t want your users to use the update functionality.
This plugin not only disables the update mechanism for the core, plugins and themes, but it also removes the update menu item from the left navigation menu in the admin dashboard.

Disable Updates for WordPress Core, Plugins and Themes

Disables the WordPress update checking and notification system for all core, plugin and theme updates.

Disable WordPress Core Update Email vs Disable Updates for WordPress Core, Plugins and Themes