Sure, but that's simply a single point in favour of Dynamo in what should have been a comprehensive analysis of strengths and weaknesses with respect to the required use case.

If they chose DynamoDB simply due to this strength (ignoring for the moment that the same thing can be achieved with native functions in Aurora), while ignoring the other things that ultimately turned out to be more important, then this again points to a flawed analysis. It's hard to see how serverless is to blame for this.