Hi there,
I am sorry for the delay of this reply. Unfortunately, there is no setting to hide the update notice to a certain user groups and this is fall under customization where as stated in our support policy we cannot support any customization.
However, there is some way that you can do:
1. Edit the php in this file:
administrator\components\com_easydiscuss\themes\default\structure\default.php
which is will be overrides whenever you updates.
2. Apply css code to hide this update notice complete to any user groups, but superuser still can now the update status on the back end dashboard
#ed .app-alert.o-alert.o-alert--danger.outdated-version {
display: none !important;
}