I think there is one exception to the above...which would be if there's already a complete show uploaded to the archive now and what you'd be uploading is a different source, but is not the complete show.
I indeed use the LMA as both an archive, but also as a supplemental backup for shows that I've uploaded. With that in mind, I recently uploaded a moe recording that was the second set from Summercamp where I didn't record the first set because I was at a different stage recording someone else. Apparently, that doesn't fly because my uploaded files have been deleted, presumably since what I uploaded was considered incomplete and there were other sources that had both sets.
That said, if your source is the ONLY source of a show and it's an incomplete show, I'm pretty sure that it's encouraged to upload it under the 'better than nothing' concept.