Weak Survey as Poster?
Now, it is my understanding that poster sessions are normally works in progress.


Not quite. Poster sessions normally readily accept work in progress. However, I have yet to see a poster session that requires the presented work to be in progress, or unfinished.

The reason why you normally see much work in progress on poster sessions besides few finished results is that authors who have complete, final results will rather aim for something more reputable than "just" a poster, by trying to publish a regular conference paper.

However, it is completely acceptable to present final results on a poster, if you deem a poster to be the best way to draw benefit from your results (e.g. get in touch with other researchers).

EDIT: As explained by the updated question, the "final results" are actually just final for a very early step in a research endeavour. It seems that they are meant to show a direction into which future research could proceed.

This kind of statements, especially when it refers to the future research that the author would like to start, is rather common on posters. Like this, posters serve two purposes:


On the one hand, they show a small contribution. Even though they are comparably abstract and superficial, the early conclusions on how several aspects can be combined and thus lead to new research questions may provide a good overview of the new topic to other researchers. In this interpretation, the content of the poster is a newly discovered research question that is possibly interesting to other people beside the poster author.
On the other hand, they serve as a request for comments on the author's work. Poster sessions are perfectly suited for finding opportunities to let experienced researchers have a look at one's work and provide comments or enter into a discussion with them. In this interpretation, the content of the poster is a kind of a research proposal.