I hadn't thought about the mobile thing. Perhaps that Japanese feature is an issue, though I suspect they can either work around it (by introducing wifi for everyone, though that could be a reason for a delay, or by cutting it out). Plenty of titles on the virtual console have cut out functionality compared with their original releases (like the lack of wifi in Animal Crossing: Wild World, or several other similar changes), and it wouldn't surprise me if the feature were to get cut.
I just hope they release it eventually. It's a guaranteed money-maker, so it wouldn't surprise me to see it out someday. Maybe they want to spread out the releases to increase profits, or to help advertise another game in the future.
Aside from the mobile thing, one concern I have is that Crystal features Kris, who wasn't in HGSS. It's been long enough that I doubt GF would care, but since they replaced Kris with Lyra in HGSS, would they be reluctant to return to Kris? That being said, FRLG didn't remake Yellow, and if anything, Yellow was even less relevant today than Crystal would be (tying in with anime plot lines from years gone by), so references to older elements/features probably isn't a concern. Plus, HGSS did include a number of Crystal references/plot elements, so hopefully Crystal's features are still considered relevant enough to be worth re-releasing.
