I'm glad you like the UI. Unfortunately, making the entire wiki public is not possible at the moment due to our focus on teams and companies. They use it to share knowledge internally and explicitly don’t want to have it indexed and publicly accessible.
It could be interesting though to expand Nuclino for the use in communities in the future as a lot of requirements overlap.
Can these WikiPages be made public to non team users? I.e., made public?
This is likely a non-issue for your product, seeing as it is team-oriented rather than community-oriented.