Perhaps I didn't explain myself very well. I don't think that the throne actually belongs to Alleria. I realize that the people would reject her, since she has been missing for so long. She is a beloved hero, but that alone usually doesn't secure the absolute loyalty of the people and the nobility. However, I do believe that the Void Lords' statement that Alleria is the rightful queen is half true. Or possible just one of the countless truths they've seen; but meaningless truths, things that are true only if separated from any context. It is not actually true, because, much like the Light, the Void never shows actual, full truths. But I do believe there is some logic behind their statement. And it is interesting that Blizzard would put that line in the comic.
(I still hope there is a Silvermoon warfront by the way, though I know it won't happen.)