Chris Biscardi discusses recent updates in Gatsby themes, focusing on the introduction of child theming and component shadowing. Child theming is an extension of the core theming algorithm that allows for a parent-child relationship between themes, enabling users with varying skill levels to modify themes more easily. This feature benefits theme authors by allowing the abstraction of logic and UI elements into multiple packages, enhancing the creation of accessible and performant sites. Biscardi highlights various use cases for child theming, such as designers altering design tokens and developers familiar with HTML, CSS, or GraphQL creating custom themes. Additionally, component shadowing has been expanded to apply to the entire src/ directory, addressing feedback from early adopters. This change simplifies theme development by allowing shadowing on templates and new directories. Biscardi hints at future developments for Gatsby themes and encourages readers to stay updated through the Gatsby blog.