Only a fool would think Kyrie actually believes the earth is flat. Holy Lord are some people gullible.
Have you actually listened to him talk about it?
There is video where he tells the media he was joking.
Link?
I'd also be interested in a link to this video, because I haven't found it.
If he was just trolling on the podcast, it was pretty elaborate because the statements about conspiracy theories are all kind of wrapped up in his worldview and his teammates act like they've heard this from him before.
It could all be a joke but if it is, he got me good.
EDIT: I'm making my way through Road Trippin (not all the episodes just ones that interest me) and I just listened to episode 14, the first one with Kyrie after the flat-Earther business hit.
They all spend the first part of the podcast defending free thinking. They don't really weigh in on any of the specific theories but it was a defense for thinking outside the mainstream and sounded like he either believes in these theories or, at the very least, is advocating against what we think of as common knowledge.
Anyway, it hits my ears like Kyrie really believes this stuff and thinks everyone's opinion should be respected.