Max Nichols of Hyrule Interview has noted how this is apparently "the first ever Zelda game" where the creator of the series does not appear in the credits (via Nintendo Everything). As mentioned by the source, Miyamoto is now 71 and is no longer "directly leading" multiple teams.
The series co-creator Takashi Tezuka has also not been featured in the latest Zelda game credits, although this isn't the first case of this. The credits also supposedly show 53 percent of the 338 people credited on Echoes of Wisdom "have never been credited in a Zelda title before".
In recent years, Miyamoto has spent his time promoting Nintendo's theme parks and more recently the Nintendo Museum. If you haven't played Zelda: Echoes of Wisdom yet, in our Nintendo Life review we called it a bold blend of new and old that was up there with the series' best.