> I would simply trigger a Lambda function once a minute (or every X minutes) using CloudWatch to fetch the latest articles and save them to an S3 bucket which I would expose and cache using CloudFront or any other CDN service.

Lot of upsides to this design, and this pretty much outlines a toned-down version of a very large, high-throughtput, low-latency globally distributed configuration system with strict write-ordering but near-realtime write-propagation guarantees a sister team worked on (though, I hear, they're redesigning it for reasons not relevant in this context). There is much to like about it.

Fetching items from S3 (fronted by a CDN or not) would require managing credentials at the client-side, though? Do-able but may require additional code for an auth-service (AWS Cognito or AWS STS or...)?