I don't think anything is serious right now, I don't think Japanese Pearlshippers might be impressed by XY based on what I'm hearing, they've already been saying how much Serena resembles Dawn. I think it's a good cause of concern to be worried at this point, as many of them really wanted Dawn to come back and felt disheartened that they were hyped up the series only for it to be unimpressive.
What seems to be the main cause of worry is that Dawn might not come back for them, despite how much they were being teased last year. And Japanese are starting to believe in the headcanon that any character sent to Johto won't appear again.
Since what's on the horizon seems to be a 4-person entourage, I assume that the series would be more similar to AG.
As long as XY doesn't promote the duet-like thing they had in DP, then it might not have an effect. I'm pretty sure that they aren't going to go all out and have Rika Matsumoto and Mayuki Makaguchi (Serena's VA; and I don't think she is popular, especially compared to Megumi Toyoguchi, Hikari's seiyuu) sing a duet like they did with Matsumoto and Toyoguchi singing "High Touch!", with Pikachu and Fennekin doing some kind of duet, can they? That'll be too obvious.
Previously, the BBS has been inactive for some time. The increase of presence of active Pearlshippers over there lately seems to me that it's still active. Also, the main site on mint.45.kg has been down for at least two weeks, and it's unknown when the site will be back up. There's also a Facebook group on Pearlshipping that's also quite active. XY has yet to impress me at this point, and I doubt whether the first few weeks can match the ratings that DP and BW had. I would have to wait and test the waters.
On another slight positive note, there was a twitter post that surfaced sometime last week where there were Pikachu and Piplup lights in the studio where the anime is aired.
https://twitter.com/joujinakata123/status/378899651224551424
To Pearlshippers, mainly Japanese Pearlshippers, anything official promotion involving Piplup is a support for Dawn and by extension, Pearlshipping (if Pikachu is also shown together with Piplup).