I have had similar thoughts Neha; I'm weighing whether or not to try this approach for a new project. I have old content that is very text heavy; if I broke it into small chunks the dev time is less because I won't make a lot of changes to what's on the slide but I get to address the cognitive overload, which could arguably be our greatest ROI here. The goal was to not make a lot of changes to the slides/design so that we could finish the project quickly....
To your question now - I've realized that if I want to use this idea, then I'm a bit challenged when it comes to contextual differentiation. If I want to provide context for my large and varied workforce, I have to touch each slide - and if I'm doing that, I'm back to a full scale project. So, I would say that micro-learning might not work if the learners you are delivering the content to need different contexts in order to understand the material.
I'm sure others are also thinking about these things; I'd welcome any comments from my "thinking partners" in the community!