Maybe it would be simpler to leave out all the fiddly details, seeing as the NP point itself mentions that it's discontinued after SPM, and just say:
Really, it's not even necessary to mention Nintendo Power at all, seeing as its placement higher in the numbered list automatically makes it overrule Prima, although that might be worth stating at the top of the section too (new stuff in italics):#'''Name from a Prima Games Strategy Guide or any other third-party guide''' A name from any officially-licensed third party guides is acceptable, but takes lower priority if it contradicts a name found in a Nintendo Power guide. For Japanese names, guides published by Shogakukan (Nintendo's official guidebook licensee) take priority over other publications.
This is a list of acceptable sources when it comes to naming an article. If a source is not present, keep moving down the list until you have found the right way to name the article, and only create a conjectural title as a last resort. If different sources give conflicting names, the source that is highest on the list gets priority, although the alternative names should still be mentioned in the article's introduction.