These Directs are basically advertisements.
Using someone's death to incite sympathy for a company and their products would be tasteless and cynical.
Iwata was a major part of the Directs and well beloved by most who watched them. Nothing wrong with giving a tribute to him since this will be the first Direct since his death.
Tasteless and cynical would be if after the tribute they announce they're now selling Iwata Amiibos that'll unlock exclusive content in Twilight Princess HD and Star Fox Zero.