Does a Meta-Study contribute to the Body-of-Research and how?

It depends on how you define the "body of research". If you see it purely as a collection of all raw data, then no, a a meta-analysis would not contribute to it. However, I would argue that most people use the term "body of knowledge" much more widely, to mean all research that has been conducted and all knowledge that has been generated and published in a field.

In order to be publishable, a meta-analysis should produce new knowledge (e.g., through new experiments or analyses, or by increasing our confidence in previously-published analyses through comparison over a larger sample size), and in that way contribute to the sum of all knowledge in the field, even if no new data points have been collected.

A meta-analysis could be considered useful if it provides one or more of the following:

• Synthesis: A research domain may have tens or even hundreds of papers. A meta-analysis could provide a synthesized summary by providing classifications and catalogs.

• New perspective: Summarizing the existing studies from a new perspective could be very interesting. It could be from the technology side (for instance, how a new technology affects the previous results) or from the people side (for instance, how existing methods are seen by a manager vs by a student).

• Research opportunities: A meta-analysis may also explain not only how the research domain has evolved (in say, last 5 years) but also reveal gaps in the field.