I think Pokemon's fanbase is ageing per se, but I feel as though it might be a conscious decision from The Pokemon Company - the comparison I would make would be comic book properties (target the core, expand the reach of your property).
They seem to be targeting an older audience, those who grew up playing Pokemon, which in turn will introduce the Pokemon brand to their loved ones, whether through the Pokemon games, apparel, tv show, etc.
Siliconnera's article about Pokemon's
decline sales is simply rubbish. As we stand, Pokemon XY have sold over 13.3 million copies (1 year release compared to 4) and will most likely achieve similar results to Black & White, 15 million.
What I would argue is that, with every successive release in Japan, we see lower sales. Pokemon mainline games have always achieved over 5 million in their home territory, but we won't see that result with XY - that decline, is related to not targeting younger children as predominantly as it once did (Youkai Watch has filled that void); hence why Pokemon XY was extremely front-loaded and the core bought it day 1.
Regardless of the
decline in Japan, the West now makes up for it; which is odd because prior to this generation, Japan would be it's best territory by a large margin.
In essence, I think TPC has realized the above. They want to continue appeal to the core, and I think Pokken Tournament is nice addition to that strategy. In regards to their
kids segment, this is the area where they need to work harder. I'm positive they will find something that will reinvigorate the brand within that market segment.
In the end, Pokemon is still one of the most bankable properties in the gaming industry and I don't think that's going to change in the long run