I certainly agree that a 7442 would serve fine on MXP route. It's not as if they are competing with another airline. But we don't have perfect knowledge of the situation and TG management may have their reasons for doing so. As for sending the A346 to NRT, NRT may be a premium destination, but a highly competitive route. So yields may not be so good.

With regards to TG website still selling F. Its quite normal. E.g. in KVS my flight was changed from a 773 to a 772. But then again, TG website still shows 773.