In other words, yes, you should be rotating what you can rotate, but this doesn't always help. Furthermore, it doesn't justify the pricing. It would make sense if this were, say, "Hey, you can now auto-rotate SSM-PS secrets for an extra $0.40/secret".
Right now it just seems weird.
[Edit: I just saw the custom rotation bit of the article. Cool; but if you're at the point of setting up lambdas for the rotation, you might as well cron a lambda on top of ParameterStore...]