i certainly think it doesn't sound like Harry is writing his own speeches. So he's effectively become a mouthpiece for her own views.
Well it wouldn’t be unusual for the highly articulate wife to help out the not so academic husband with the boring writing stuff, no.
But a huge leap to say he’s become a mouthpiece for her. Also a very negative reflection on Harry. Is he not big and bold enough to champion what he believes in?
If he’s talking about things he doesn’t value then that’s a big failing on his part.