Unity Pro with free iOS and Android?

I am considering upgrading to Unity Pro shortly, and while I intend to upgrade to pro licences of iOS and Android eventually, for the time being I would rather continue to use the free versions. Is this possible, or once I upgrade to Unity Pro do I also have to upgrade to iOS and Android Pro in order to make builds?

A simple question, but the purchase page is not clear on this. Thanks!

I am currently using a Pro version of Unity desktop (educational Pro, but still Pro) and have the free versions of iOS and Android. Has not been an issue for me in building for iOS.

On the Unity Store page, it says that the iOS and Android licenses are “Optional add-ons for Unity Pro.”