That's actually the biggest issue here. I follow Canadian politics, I live in the capital, I know Trudeau was joking.
But his image is so flakey that most casual observers thought he was serious.
Truth is, Justin Trudeau is completely full of shit. He's "progressive" because he needed to steal the base from the actual progressives, the NDP.
He could give a fuck about pronouns, LGBTQ issues, human rights, and climate change. He cares about power.
If anything, his joke about "peoplekind" was a crack in the facade, and he was making fun if pronoun politics.