There is no written standard, although in the 2010's on Internet message boards the standard regarding blaming thematic errors and Onstage theme park mistakes tends to go like this;
Any Mistake From 1955-56: Doesn't count because Walt was inventing an entirely new industry.
Any Mistake From 1957-1966: Doesn't count because Walt did it. Or, doesn't count because Americans were less sophisticated back then and didn't know any better. Or, doesn't count because Walt and his top Imagineers were working on the World's Fair pavilions and they were busy elsewhere. Did I mention that if Walt did it, it doesn't count?
Any Mistake From 1967-1971: Doesn't count because the Company was reeling from the sudden loss of Walt and focusing on getting Disney World open.
Any Mistake From 1972-1983: Doesn't count because Card Walker and Ron Miller were in charge and it was a sleepy and unsuccessful era for the Company as a whole.
Any Mistake From 1984-1995: Doesn't count because Eisner had saved the Company and big new E Tickets were opening all over the place.
Any Mistake From 1996-2003: These mistakes count because of PRESSLER!
Any Mistake From 2004-2006: Doesn't count because of the 50th Anniversary.
Any Mistake From 2007-2011: These count because of Jay Rasulo and One Disney and the state of Florida and California's Department of Safety and Health (DOSH), in that order. Also Princesses. And Pixar.
Any Mistake Made in 2012: Doesn't count because of Cars Land.
Any Mistake Made in 2013: These mistakes count because of STARBUCKS!
Any questions? Feel free to print this out and post it on your fridge for future reference.