NOT tell their kids something they believe is true "because it has not been well-researched"?
(And who is deciding whether something is well-researched or not?)

Nobody would do that. I think the most open-minded of parents might try to explain both sides and then tell their kids that as they grow up and learn more, they will make up their own minds, but we will almost always explain what WE believe is true....because when you believe something yourself, you generally think that you are right. That's just human nature.

I seriously doubt that the religious among us would tell their kids "Well, mommy and I believe in one God, and that he created the heavens and the earth. But that's just us. You should read up on the subject and find out what makes sense to you." LOL!

But wouldn't it be fun if they did?