Hi, I am not entirely sure if this is a bug or feature request...
I currently have one level, Premium Plugins module enabled. I have some subsites addigned to Pro Sites and some (custom clients) that I keep outside Pro Sites levels.
What I do:
I install a new plugin as Network Admin. I do not activate the plugin
Newly installed plugins shows on the list of plugins for Subsite Admins (though not active). When I go, as a Super Admin, to the Premium Plugins page in Pro Sites, I see "None" selected for those new plugins. If I then click Save, finally the plugin will be hidden from Subsite Admins. This behavior exists for all subsites, so both sites that have Pro Sites levels applied and subsites outside of Pro Sites.
What I would expect:
New plugins installed by the Super Admin to never show for Subsite Admins, unless explicitly made visible in the Premium Plugins page by selecting a Level or Anyone.