Should systematic reviews be submitted to journals as original or review articles? In the Information for Authors of several (health) related journals, manuscript types may include original research and review articles, among others. 

I thought systematic reviews (whether quantitative or qualitative) should be submitted as review submissions, as opposed to, for example, original studies with novel findings based on data collected or analyzed by authors. However, the guides in those journals say a review requires an unstructured abstract, as in narrative reviews.

In this answer, review articles can be considered original observations. So why do some journals distinguish between review articles and original research? And, under which category should systematic reviews be submitted to these journals?
I can see a good case to be made on either side:


A systematic review, unlike a more traditional narrative review, is often an explicit numerical meta-analysis of prior data.  Its systematicity allows it to be an actual experiment with objectively verifiable conclusions, and thus it may be reasonably considered original research on a new data set drawn from the literature. 
Systematic reviews still, however, are organization and analysis of other studies, and so could be grouped in with other reviews.


Since both of these are reasonable, I suspect that there is no way to tell which perspective a particular publication subscribes to without reading their guidance to authors or asking their editorial staff (who will no doubt be happy to answer the question).