Zapier has a built-in RSS Generator, to which your zap can add content for retrieval by RSS readers.
Here's what I know so far, specifically in comparison to Webflow's RSS generator;
Pros;
Cons;
Upshot
You can trigger your Zap either with your own RSS ( and have your zap automation re-form it for export ) - however you will only have the data that was in the original RSS, plus whatever else you Zap can acquire.
This means, e.g. this is not the right approach for getting the Article body rich text content.
Instead, I'd use Webflow's CMS Item Created trigger to do this. That way, you have access to the full CMS content, and can use it to build e.g. Author info. However, in Zapier, Webflow's triggers require a paid plan.