The specific question was as follows when it was closed (edits may occur after I post this):
A popular fan theory states that Super Mario Bros. 3 was in actuality just a performance or stage play, as written about by Cracked and Dorkly among others. Is there any basis to this assertment? Has it been confirmed or denied?
I believe that the question falls foul of the close reasons because of the
Has it been confirmed or denied? line.
Without that people can offer in game answers, dissect manuals and so on. As well as the current answer from the OP being useful.
With the line, it reads (to a number of people)
what is the official word from the developer?. The answer from the asker is a video of the developer confirming the word.
Also, with that interpretation you are scoping the possible answers to discussions on the developer's intent.
I'm not going to go into whether the site should allow developer intent questions (I don't see a problem with the current allowed questions), but in any case the question would be more useful without that last line. At least it offers more answers/in-game research etc than some quote from a developer's twitter feed or interview.