My view is actually more realistic than negative, Game Freak can't get away with just using the same old stuff forever and expect it to work every single time, with the prime example being Kanto Pokemon getting most, if not, all the attention. That's a telltale sign that a company has trouble keeping sales up with new stuff instead.
It is quite a coincidence to have that number there; it is also the same date as the Pokemon Direct that revealed Sun & Moon.
I don't think that any of the SM companions will stick around into Gen 8.
I think Lillie sticking around could be a possibility... she seems to be a relatively popular character and it's not like she doesn't take off on her own adventure at the end of Sun and Moon- granted, to Kanto, but with how the anime deviates from everything, the idea of her going off with Ash instead wouldn't be a stretch.
;P Serena who?
