Theming Issue as PrimeNG evolves

[thelemondropkid]

Hello folks.

Is it possible to use a theme created in PrimeNG 8 in a project using PrimeNG 9, or do I have to create a new theme from scratch?
When I look at the change log it's difficult to determine if the CSS of a version 8 component will be impacted in newer releases as new functionality and styling is added.

Any help will be appreciated.