I don't get what you mean by Special typing being false? Fact : Fire, Water, Electric, Psychic, Dark, Grass, Ice and Dragon were all Special types. Fact : We've had Fire, Water, Electric, Psychic, Dark, Grass and Ice eeveelutions. What part of this is false? If patterns were to continue the next eeveelution we would have gotten would've been Dragon. And if Fairy were to placed in Physical or Special base, it's pretty obvious it's be Special. Yes this is all speculation, but it was never "confirmed false".
So the Sylveon movie was released and no new Eevee, in my book that just makes it less likely, but never impossible. And we were never told that Sylveon "is the only new eeveelution", it's just highly unlikely.
Fairy is not Special typed. That proves that the pattern is false. It cannot be specil typed either as it never existed during the Third Generation when Physical/Special were split by type. The fact a new eevee evolution was shown that was not of the special type means that them being special types is no longer a defining factor.
Yes all media covering Sylveon markets it as the only new eevee evolution this generation. It is refered to as the new. Not the newest, one of the new, or a new. The put focus on Sylveon. Corocoro didn't leave extra space and marketed it as the only new one. The movie says all evolution for eevee are in it. It stops on Sylveon.
Gamefreak has also said they follow no set patterns when designing things for the games. Eevee having pairs was nothing but coincedence. Sylveon is marketed as the only new evolution for Eevee, chances are it is the only new evolution for eevee.
Since its sorta relevant, mewtwo had one form in the movie, so good chance there is only one form fo it as well. If another form existed it would have been in the movie.
As for Xerneas, I just said that the deer on yggdrasil doesn't represent life. Why would Xerneas represent life if based on one of the four deer that live there. Only deer that represents life is a japanese myth. Xerneas is found in a forest so who is to say he's not a forest guardian? All the new info from Gamefreak pushes for more Japanese cultured legends than norse ones. Both Xerneau and Yveltal have more accurate relations with the japanese myths than norse ones.