There are a lot of factors that need to be taken into consideration before anyone assumes the new Pokemon is or isn't a Nosepass/Probopass evolution. GF has showed us that they're willing to turn an average Pokemon into a larger, unnecessary one (Dusknoir, Magmortar, even Probopass himself, if you will) as well as add some interesting new methods of evolution. Looking at the color scheme, Probopass' stats, and the possibility that this could be a Nosepass alternate evolution.
It could also be an entirely new line of Pokemon entirely. GF has also made Pokemon that look similar, but are totally unrelated. This new Pokemon has a similar color-scheme and rocky-shape that is a bit like Nosepass', but nothing definite. It's too soon to tell, the pictures are blurry, we have no official art, a name, or any information on it at all. Personally, I'm neutral to the debate...this Pokemon is a total wild-card, and could go in any direction. We should just wait for a name (since if it doesn't involve pass or noses, it's probably unrelated) to clear everything up, and stop wondering which it is. It truly could be anything...you never know with GF anymore.