Hide Genesis upgrade notice from new site registration login

Hello!

I'm using a mu-plugin from this post to hide the Genesis upgrade notice
https://premium.wpmudev.org/forums/topic/hide-genesis-framework-upgraded-notice-from-non-super-admin
This works well when users login in from here
http://mainsite.com/subsite/wp-login.php
They land on their dashboard & see the welcome message I set up using the Ultimate Branding plugin.

However, when someone has just successfully registered a new site, they see the screen that states they'll be receiving an email and it shows their login details, username & admin url. When they click on the admin link provided which is
http://mainsite.com/subsite/wp-admin
They are directed to the following where they see information about the version of Genesis
http://mainsite.com/subsite/wp-admin/admin.php?page=genesis&upgraded=true

Is there something that can be done so that when someone clicks on the link after they've signed up for a new site they are directed to http://mainsite.com/subsite/wp-admin/index.php?

Thank you!
Debbie