No, this is considered as qualitative analysis. This follows "Grounded theory" research method of refining and categorizing different studies to develop a theory(ies) through constant comparative method and theoretical sampling.

I looked up the grounded theory in

G. Allan, "A Critique of Using Grounded Theory as a Research Method," Electronic Journal of Business Research Methods, vol. 2, no. 1 (2003) pp. 1-10.

It mentioned that "grounded theory is quite different from the traditional scientific model of research, where the researcher chooses an existing theoretical framework, develops one or more hypotheses derived from that framework, and only then collects data for the purpose of assessing the validity of the hypotheses" . This means that Meta data research can fall under grounded theory , however, this might have exceptions , as not all such type of papers starts with a hypothesis .

I would say that a systematic review that does not employ statistical analyses on the data obtained from the original studies is a qualitative study. I would only consider a meta-analysis (or any other statistical method of synthesising data) a quantitative approach. That said, there are many different qualitative reviews (e.g., narrative, systematic) and quantitative reviews (e.g., meta-analysis, mega-analysis).

If you are looking to review the methods used to study a certain phenomenon, I think you will conduct a qualitative review. Perhaps you will count how many experimental studies, how many correlational studies etc. but this is not a meta-analysis. If you have made categories _before_ you start your data coding, you are not employing grounded theory. Grounded theory seems to suggest you have yet no idea on what kind of methods exist or have been used in this field.

But in case of using statistical method for synthesis of data ( meta/ mega data or else), this would apply for using numerical data, but these data is still unitless ( in most cases ) , would that be quantitative or just qualitative ?