I never really see or hear anything about songs that get tied in with NHK Taiga dramas and the people that watch them are not people who would normally go out of the way to buy Ayumi's cd. Plus we don't know what extent the song will even be used. And the press conference for the drama has already been held. I'd be surprised if they hold another one just to say Ayumi will have a song in it.
Same thing with the Tinkerbell movie, it's hard to say exactly in what capacity the song will be used. And once again, its not really an audience that is gonna go out and buy the cd (or even have the means to ^_^). Only if they beg their parents will they get the cd and even then, most children are more likely to beg their parents for a Tinkerbell doll or something I think.
Of course it won't HURT cd sales, but the amount they help is probably minimal.
These haven't been reported by the morning news sources since they were announced which usually means the tie ins are not considered very major.