One request can change several slides
Google's October 30 announcement says you can ask Gemini, through the Google Slides side panel, to change text or visual styles across several slides or a whole presentation. These remain editable Google Slides, and Gemini supplies a summary of its changes. Undo and version history let you go back. [1]
When you can try it
The English-language rollout began October 29 and may take more than 15 days. Eligible plans include Business and Enterprise Standard/Plus, Google AI Pro/Ultra, and Google AI Pro for Education. Google lists no separate administrator switch for this feature. [1]
Google also says its higher promotional limits for creating multi-slide presentations will last through at least December 1; it will announce later limits per person. That offer concerns creating presentations. We have not tried the editing feature ourselves. [1]
Our take
Start with a copy and ask for one clear change, such as using the same heading style throughout. Then check the figures, wording, and layout on every affected slide. A presentation can look more polished while still saying something wrong.